From 2dff876f0f02fa3a440a434f0db6fb7c671ee446 Mon Sep 17 00:00:00 2001
From: ghidra1 <ghidra1@users.noreply.github.com>
Date: Wed, 20 Mar 2024 17:43:49 -0400
Subject: [PATCH] GP-4341 Force retained checkout if file is in-use during
 checkin or add-to-version-control.  Deprecated upgrade concept during
 checkin. Revised manner in which file open for update is updated following a
 version control operation (perform DBHandle update).

---
 .../DebuggerStaticMappingServicePlugin.java   |   7 +-
 .../service/modules/ProgramModuleIndexer.java |   8 +-
 .../utils/DomainFolderChangeAdapter.java      |  72 ---
 .../service/url/ProjectExperimentsTest.java   |   5 -
 .../database/program/DBTraceProgramView.java  |   6 -
 .../program/DBTraceProgramViewRegisters.java  |   9 +-
 .../RepositoryFileUpgradeScript.java          |   2 +-
 .../archive/DataTypeManagerHandler.java       |  16 -
 .../core/progmgr/MultiProgramManager.java     |  44 --
 .../DomainFolderChangesDisplayPlugin.java     |   5 -
 .../app/util/headless/HeadlessAnalyzer.java   |   2 +-
 .../data/DefaultProjectDataTest.java          |  14 -
 .../base/project/FakeSharedProject.java       |  16 +-
 .../vt/api/db/VTSessionContentHandler.java    |  21 +-
 .../vt/gui/plugin/VTControllerImpl.java       |  83 ---
 .../DB/src/main/java/db/DBHandle.java         |  39 +-
 .../src/main/java/db/buffers/BufferMgr.java   | 148 +++--
 .../db/buffers/LocalManagedBufferFile.java    |   5 +-
 .../ghidra/framework/data/ContentHandler.java |  58 +-
 .../framework/data/DBContentHandler.java      |   7 +-
 .../framework/data/DefaultCheckinHandler.java |   2 +-
 .../framework/data/DomainFileIndex.java       |  36 +-
 .../framework/data/DomainFileProxy.java       |   2 +-
 .../data/DomainFolderChangeListenerList.java  |  16 +-
 .../framework/data/DomainObjectAdapter.java   |  13 +-
 .../framework/data/DomainObjectAdapterDB.java |  40 +-
 .../ghidra/framework/data/GhidraFile.java     |  10 +-
 .../ghidra/framework/data/GhidraFileData.java | 516 ++++++++++--------
 .../framework/data/LinkedGhidraFile.java      |   2 +-
 .../main/datatable/ProjectDataTablePanel.java |  26 +-
 .../main/datatree/ChangeManager.java          |  29 -
 .../framework/main/datatree/CheckInTask.java  |  31 +-
 .../main/datatree/VersionControlTask.java     |  30 +-
 .../actions/VersionControlAddAction.java      |   3 +-
 .../ghidra/framework/model/DomainFile.java    |  52 +-
 .../model/DomainFolderChangeListener.java     |  62 ++-
 .../model/DomainFolderListenerAdapter.java    |  19 -
 .../framework/model/TestDummyDomainFile.java  |   2 +-
 .../DataTypeArchiveContentHandler.java        |  24 +-
 .../program/database/DataTypeArchiveDB.java   |   3 -
 .../database/ProgramContentHandler.java       |  27 +-
 .../ghidra/program/database/ProgramDB.java    |   6 -
 .../ghidra/program/model/listing/Program.java |   6 -
 .../ghidra/program/model/StubProgram.java     |   5 -
 .../ProgramManagerPluginScreenShots.java      |   4 +-
 .../datatree/VersionControlAction1Test.java   |  14 +-
 46 files changed, 695 insertions(+), 852 deletions(-)
 delete mode 100644 Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/utils/DomainFolderChangeAdapter.java

diff --git a/Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/service/modules/DebuggerStaticMappingServicePlugin.java b/Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/service/modules/DebuggerStaticMappingServicePlugin.java
index c57aa2173b..f4be7da5fb 100644
--- a/Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/service/modules/DebuggerStaticMappingServicePlugin.java
+++ b/Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/service/modules/DebuggerStaticMappingServicePlugin.java
@@ -32,7 +32,8 @@ import ghidra.app.plugin.core.debug.DebuggerPluginPackage;
 import ghidra.app.plugin.core.debug.event.TraceClosedPluginEvent;
 import ghidra.app.plugin.core.debug.event.TraceOpenedPluginEvent;
 import ghidra.app.plugin.core.debug.service.modules.DebuggerStaticMappingProposals.ModuleMapProposalGenerator;
-import ghidra.app.plugin.core.debug.utils.*;
+import ghidra.app.plugin.core.debug.utils.ProgramLocationUtils;
+import ghidra.app.plugin.core.debug.utils.ProgramURLUtils;
 import ghidra.app.services.*;
 import ghidra.async.AsyncDebouncer;
 import ghidra.async.AsyncTimer;
@@ -60,6 +61,7 @@ import ghidra.util.datastruct.ListenerSet;
 import ghidra.util.exception.CancelledException;
 import ghidra.util.task.TaskMonitor;
 
+//@formatter:off
 @PluginInfo(
 	shortDescription = "Debugger static mapping manager",
 	description = "Track and manage static mappings (program-trace relocations)",
@@ -70,8 +72,9 @@ import ghidra.util.task.TaskMonitor;
 		TraceOpenedPluginEvent.class, TraceClosedPluginEvent.class, },
 	servicesRequired = { ProgramManager.class, DebuggerTraceManagerService.class, },
 	servicesProvided = { DebuggerStaticMappingService.class, })
+//@formatter:on
 public class DebuggerStaticMappingServicePlugin extends Plugin
-		implements DebuggerStaticMappingService, DomainFolderChangeAdapter {
+		implements DebuggerStaticMappingService, DomainFolderChangeListener {
 
 	protected class MappingEntry {
 		private final TraceStaticMapping mapping;
diff --git a/Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/service/modules/ProgramModuleIndexer.java b/Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/service/modules/ProgramModuleIndexer.java
index ba48220be5..20e8230328 100644
--- a/Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/service/modules/ProgramModuleIndexer.java
+++ b/Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/service/modules/ProgramModuleIndexer.java
@@ -22,7 +22,6 @@ import java.util.stream.Collectors;
 import com.google.gson.Gson;
 import com.google.gson.reflect.TypeToken;
 
-import ghidra.app.plugin.core.debug.utils.DomainFolderChangeAdapter;
 import ghidra.app.plugin.core.debug.utils.ProgramURLUtils;
 import ghidra.framework.model.*;
 import ghidra.framework.options.Options;
@@ -33,7 +32,7 @@ import ghidra.program.model.listing.Program;
 import ghidra.trace.model.modules.TraceModule;
 
 // TODO: Consider making this a front-end plugin?
-public class ProgramModuleIndexer implements DomainFolderChangeAdapter {
+public class ProgramModuleIndexer implements DomainFolderChangeListener {
 	public static final String MODULE_PATHS_PROPERTY = "Module Paths";
 	private static final Gson JSON = new Gson();
 
@@ -288,11 +287,6 @@ public class ProgramModuleIndexer implements DomainFolderChangeAdapter {
 		refreshIndex(file);
 	}
 
-	@Override
-	public void domainFileObjectReplaced(DomainFile file, DomainObject oldObject) {
-		refreshIndex(file);
-	}
-
 	@Override
 	public void domainFileObjectOpenedForUpdate(DomainFile file, DomainObject object) {
 		if (disposed) {
diff --git a/Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/utils/DomainFolderChangeAdapter.java b/Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/utils/DomainFolderChangeAdapter.java
deleted file mode 100644
index 9528dc4a2e..0000000000
--- a/Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/utils/DomainFolderChangeAdapter.java
+++ /dev/null
@@ -1,72 +0,0 @@
-/* ###
- * IP: GHIDRA
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- * 
- *      http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package ghidra.app.plugin.core.debug.utils;
-
-import ghidra.framework.model.*;
-
-public interface DomainFolderChangeAdapter extends DomainFolderChangeListener {
-	@Override
-	default void domainFileAdded(DomainFile file) {
-	}
-
-	@Override
-	default void domainFolderAdded(DomainFolder folder) {
-	}
-
-	@Override
-	default void domainFolderRemoved(DomainFolder parent, String name) {
-	}
-
-	@Override
-	default void domainFileRemoved(DomainFolder parent, String name, String fileID) {
-	}
-
-	@Override
-	default void domainFolderRenamed(DomainFolder folder, String oldName) {
-	}
-
-	@Override
-	default void domainFileRenamed(DomainFile file, String oldName) {
-	}
-
-	@Override
-	default void domainFolderMoved(DomainFolder folder, DomainFolder oldParent) {
-	}
-
-	@Override
-	default void domainFileMoved(DomainFile file, DomainFolder oldParent, String oldName) {
-	}
-
-	@Override
-	default void domainFolderSetActive(DomainFolder folder) {
-	}
-
-	@Override
-	default void domainFileStatusChanged(DomainFile file, boolean fileIDset) {
-	}
-
-	@Override
-	default void domainFileObjectReplaced(DomainFile file, DomainObject oldObject) {
-	}
-
-	@Override
-	default void domainFileObjectOpenedForUpdate(DomainFile file, DomainObject object) {
-	}
-
-	@Override
-	default void domainFileObjectClosed(DomainFile file, DomainObject object) {
-	}
-}
diff --git a/Ghidra/Debug/Debugger/src/test/java/ghidra/app/plugin/core/debug/service/url/ProjectExperimentsTest.java b/Ghidra/Debug/Debugger/src/test/java/ghidra/app/plugin/core/debug/service/url/ProjectExperimentsTest.java
index e0c6d45e19..adae9bb769 100644
--- a/Ghidra/Debug/Debugger/src/test/java/ghidra/app/plugin/core/debug/service/url/ProjectExperimentsTest.java
+++ b/Ghidra/Debug/Debugger/src/test/java/ghidra/app/plugin/core/debug/service/url/ProjectExperimentsTest.java
@@ -131,11 +131,6 @@ public class ProjectExperimentsTest extends AbstractGhidraHeadedIntegrationTest
 			log("File status changed: file=" + file + " idSet=" + fileIDset);
 		}
 
-		@Override
-		public void domainFileObjectReplaced(DomainFile file, DomainObject oldObject) {
-			log("File object replaced: file=" + file + " oldObject=" + obj(oldObject));
-		}
-
 		@Override
 		public void domainFileObjectOpenedForUpdate(DomainFile file, DomainObject object) {
 			log("File object opened for update: file=" + file + " object=" + obj(object));
diff --git a/Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/program/DBTraceProgramView.java b/Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/program/DBTraceProgramView.java
index 74bc0e318e..b8c3e62b49 100644
--- a/Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/program/DBTraceProgramView.java
+++ b/Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/program/DBTraceProgramView.java
@@ -1045,12 +1045,6 @@ public class DBTraceProgramView implements TraceProgramView {
 		return language.getAddressFactory().getAllAddresses(addrStr, caseSensitive);
 	}
 
-	@Override
-	public void invalidate() {
-		// TODO: I imagine I'll find out who uses this pretty quick....
-		throw new UnsupportedOperationException();
-	}
-
 	@Override
 	public Register getRegister(String name) {
 		return language.getRegister(name);
diff --git a/Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/program/DBTraceProgramViewRegisters.java b/Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/program/DBTraceProgramViewRegisters.java
index 2e0bd8c1e6..b707c517b3 100644
--- a/Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/program/DBTraceProgramViewRegisters.java
+++ b/Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/program/DBTraceProgramViewRegisters.java
@@ -260,11 +260,6 @@ public class DBTraceProgramViewRegisters implements TraceProgramView {
 		return view.parseAddress(addrStr, caseSensitive);
 	}
 
-	@Override
-	public void invalidate() {
-		view.invalidate();
-	}
-
 	@Override
 	public Register getRegister(String name) {
 		return view.getRegister(name);
@@ -685,7 +680,7 @@ public class DBTraceProgramViewRegisters implements TraceProgramView {
 	}
 
 	@Override
-	public TraceProgramView getViewRegisters(TraceThread thread, boolean createIfAbsent) {
-		return view.getViewRegisters(thread, createIfAbsent);
+	public TraceProgramView getViewRegisters(TraceThread t, boolean createIfAbsent) {
+		return view.getViewRegisters(t, createIfAbsent);
 	}
 }
diff --git a/Ghidra/Features/Base/ghidra_scripts/RepositoryFileUpgradeScript.java b/Ghidra/Features/Base/ghidra_scripts/RepositoryFileUpgradeScript.java
index 78e207546c..774e2e277a 100644
--- a/Ghidra/Features/Base/ghidra_scripts/RepositoryFileUpgradeScript.java
+++ b/Ghidra/Features/Base/ghidra_scripts/RepositoryFileUpgradeScript.java
@@ -208,7 +208,7 @@ public class RepositoryFileUpgradeScript extends GhidraScript {
 				dobj.release(this);
 				dobj = null;
 				if (df.isVersioned()) {
-					df.checkin(checkinHandler, false, monitor);
+					df.checkin(checkinHandler, monitor);
 					println("Repository file upgraded: " + df.getPathname());
 				}
 				else {
diff --git a/Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/archive/DataTypeManagerHandler.java b/Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/archive/DataTypeManagerHandler.java
index 85e41b4365..2306fb02f6 100644
--- a/Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/archive/DataTypeManagerHandler.java
+++ b/Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/archive/DataTypeManagerHandler.java
@@ -1639,22 +1639,6 @@ public class DataTypeManagerHandler {
 			// ignore
 		}
 
-		@Override
-		public void domainFileObjectReplaced(DomainFile file, DomainObject oldObject) {
-			if (oldObject instanceof DataTypeArchiveDB) {
-				for (Archive archive : openArchives) {
-					if (archive instanceof ProjectArchive) {
-						ProjectArchive projectArchive = (ProjectArchive) archive;
-						DomainObject domainObject = projectArchive.getDomainObject();
-						if (domainObject == oldObject) {
-							replaceArchiveWithFile(projectArchive, file);
-							return;
-						}
-					}
-				}
-			}
-		}
-
 		@Override
 		public void domainFileRenamed(DomainFile file, String oldName) {
 			if (!DataTypeArchiveContentHandler.DATA_TYPE_ARCHIVE_CONTENT_TYPE
diff --git a/Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/progmgr/MultiProgramManager.java b/Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/progmgr/MultiProgramManager.java
index 72862acd04..acd7db4b74 100644
--- a/Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/progmgr/MultiProgramManager.java
+++ b/Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/progmgr/MultiProgramManager.java
@@ -23,13 +23,9 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Collectors;
 
-import org.jdom.Element;
-
 import ghidra.app.events.*;
 import ghidra.app.nav.Navigatable;
 import ghidra.app.services.*;
-import ghidra.app.util.task.OpenProgramRequest;
-import ghidra.app.util.task.OpenProgramTask;
 import ghidra.framework.data.DomainObjectAdapterDB;
 import ghidra.framework.model.*;
 import ghidra.framework.plugintool.PluginTool;
@@ -38,7 +34,6 @@ import ghidra.program.model.address.Address;
 import ghidra.program.model.listing.Program;
 import ghidra.util.Msg;
 import ghidra.util.Swing;
-import ghidra.util.task.TaskLauncher;
 
 /**
  * Class for tracking open programs in the tool.
@@ -49,7 +44,6 @@ class MultiProgramManager implements TransactionListener {
 	private PluginTool tool;
 	private ProgramInfo currentInfo;
 	private TransactionMonitor txMonitor;
-	private MyFolderListener folderListener;
 
 	private Runnable programChangedRunnable;
 	private boolean hasUnsavedPrograms;
@@ -72,8 +66,6 @@ class MultiProgramManager implements TransactionListener {
 		txMonitor = new TransactionMonitor();
 		txMonitor.setName("Transaction Open (Program being modified)");
 		tool.addStatusComponent(txMonitor, true, true);
-		folderListener = new MyFolderListener();
-		tool.getProject().getProjectData().addDomainFolderChangeListener(folderListener);
 
 		programChangedRunnable = () -> {
 			if (tool == null) {
@@ -111,7 +103,6 @@ class MultiProgramManager implements TransactionListener {
 	}
 
 	void dispose() {
-		tool.getProject().getProjectData().removeDomainFolderChangeListener(folderListener);
 		fireActivatedEvent(null);
 
 		for (Program p : programMap.keySet()) {
@@ -442,41 +433,6 @@ class MultiProgramManager implements TransactionListener {
 //==================================================================================================
 // Inner Classes
 //==================================================================================================
-	private class MyFolderListener extends DomainFolderListenerAdapter {
-
-		@Override
-		public void domainFileObjectReplaced(DomainFile file, DomainObject oldObject) {
-
-			/**
-			 * Special handling for when a file is checked-in.  The existing program has be moved
-			 * to a proxy file (no longer in the project) so that it can be closed and the program
-			 * re-opened with the new version after the check-in merge.
-			 */
-
-			if (!programMap.containsKey(oldObject)) {
-				return;
-			}
-			Element dataState = null;
-			if (currentInfo != null && currentInfo.program == oldObject) {
-				// save dataState as though the project state was saved and re-opened to simulate
-				// recovering after closing the program during this swap
-				dataState = tool.saveDataStateToXml(true);
-			}
-			OpenProgramTask openTask = new OpenProgramTask(file, DomainFile.DEFAULT_VERSION, this);
-			openTask.setSilent();
-			new TaskLauncher(openTask, tool.getToolFrame());
-			OpenProgramRequest openProgramReq = openTask.getOpenProgram();
-			if (openProgramReq != null) {
-				plugin.openProgram(openProgramReq.getProgram(),
-					dataState != null ? ProgramManager.OPEN_CURRENT : ProgramManager.OPEN_VISIBLE);
-				openProgramReq.release();
-				removeProgram((Program) oldObject);
-				if (dataState != null) {
-					tool.restoreDataStateFromXml(dataState);
-				}
-			}
-		}
-	}
 
 	class ProgramInfo implements Comparable<ProgramInfo> {
 
diff --git a/Ghidra/Features/Base/src/main/java/ghidra/app/plugin/debug/DomainFolderChangesDisplayPlugin.java b/Ghidra/Features/Base/src/main/java/ghidra/app/plugin/debug/DomainFolderChangesDisplayPlugin.java
index 93e980b94b..86b57105bb 100644
--- a/Ghidra/Features/Base/src/main/java/ghidra/app/plugin/debug/DomainFolderChangesDisplayPlugin.java
+++ b/Ghidra/Features/Base/src/main/java/ghidra/app/plugin/debug/DomainFolderChangesDisplayPlugin.java
@@ -132,11 +132,6 @@ public class DomainFolderChangesDisplayPlugin extends Plugin
 			Boolean.toString(fileIDset));
 	}
 
-	@Override
-	public void domainFileObjectReplaced(DomainFile file, DomainObject oldObject) {
-		provider.addText("domainFileObjectReplaced: " + file.getPathname());
-	}
-
 	@Override
 	public void domainFileObjectOpenedForUpdate(DomainFile file, DomainObject object) {
 		provider.addText("domainFileObjectOpenedForUpdate: " + file.getPathname());
diff --git a/Ghidra/Features/Base/src/main/java/ghidra/app/util/headless/HeadlessAnalyzer.java b/Ghidra/Features/Base/src/main/java/ghidra/app/util/headless/HeadlessAnalyzer.java
index 33f5fb2f0c..66163fc318 100644
--- a/Ghidra/Features/Base/src/main/java/ghidra/app/util/headless/HeadlessAnalyzer.java
+++ b/Ghidra/Features/Base/src/main/java/ghidra/app/util/headless/HeadlessAnalyzer.java
@@ -1488,7 +1488,7 @@ public class HeadlessAnalyzer {
 					public boolean createKeepFile() throws CancelledException {
 						return false;
 					}
-				}, true, TaskMonitor.DUMMY);
+				}, TaskMonitor.DUMMY);
 				Msg.info(this, "REPORT: Committed file changes to repository: " + df.getPathname());
 			}
 			catch (IOException e) {
diff --git a/Ghidra/Features/Base/src/test.slow/java/ghidra/framework/data/DefaultProjectDataTest.java b/Ghidra/Features/Base/src/test.slow/java/ghidra/framework/data/DefaultProjectDataTest.java
index 09e77fbbaa..9be87dcce7 100644
--- a/Ghidra/Features/Base/src/test.slow/java/ghidra/framework/data/DefaultProjectDataTest.java
+++ b/Ghidra/Features/Base/src/test.slow/java/ghidra/framework/data/DefaultProjectDataTest.java
@@ -701,20 +701,6 @@ public class DefaultProjectDataTest extends AbstractGhidraHeadedIntegrationTest
 				oldParent.getPathname(), oldName));
 		}
 
-		@Override
-		public void domainFileObjectReplaced(DomainFile file, DomainObject oldObject) {
-			// not tested
-		}
-
-		@Override
-		public void domainFileObjectOpenedForUpdate(DomainFile file, DomainObject object) {
-			// not tested
-		}
-
-		@Override
-		public void domainFileObjectClosed(DomainFile file, DomainObject object) {
-			// not tested
-		}
 	}
 }
 
diff --git a/Ghidra/Features/Base/src/test/java/ghidra/base/project/FakeSharedProject.java b/Ghidra/Features/Base/src/test/java/ghidra/base/project/FakeSharedProject.java
index 3de5d6e918..9197c68465 100644
--- a/Ghidra/Features/Base/src/test/java/ghidra/base/project/FakeSharedProject.java
+++ b/Ghidra/Features/Base/src/test/java/ghidra/base/project/FakeSharedProject.java
@@ -58,6 +58,7 @@ public class FakeSharedProject {
 	private GhidraProject gProject;
 	private TestProgramManager programManager = new TestProgramManager();
 	private FakeRepository repo;
+	private boolean isFileSharingEnabled; // set true if multiple projects share repo files
 
 	public FakeSharedProject(FakeRepository repo, User user) throws IOException {
 
@@ -85,6 +86,14 @@ public class FakeSharedProject {
 		invokeInstanceMethod("setVersionedFileSystem", pd, argTypes(FileSystem.class), args(fs));
 	}
 
+	/**
+	 * Mark project as sharing file with another project via a common repo.
+	 * This is needed to bypass check performed by assertFileInProject
+	 */
+	public void enableFileSharing() {
+		isFileSharingEnabled = true;
+	}
+
 	/**
 	 * Get the ghidra project
 	 * @return the ghidra project
@@ -162,6 +171,7 @@ public class FakeSharedProject {
 	public DomainFile getDomainFile(String filepath) {
 		Project project = getGhidraProject().getProject();
 		ProjectData projectData = project.getProjectData();
+		refresh(); // force refresh since we do not employ repo listener
 		DomainFile df;
 		if (filepath.startsWith("/")) {
 			df = projectData.getFile(filepath);
@@ -287,7 +297,7 @@ public class FakeSharedProject {
 			}
 		};
 
-		df.checkin(ch, false, TaskMonitor.DUMMY);
+		df.checkin(ch, TaskMonitor.DUMMY);
 		repo.refresh();
 	}
 
@@ -387,6 +397,10 @@ public class FakeSharedProject {
 			throw new IllegalArgumentException("DomainFile cannot be null");
 		}
 
+		if (isFileSharingEnabled) {
+			return;
+		}
+
 		ProjectLocator pl = df.getProjectLocator();
 		ProjectLocator mypl = getProjectData().getProjectLocator();
 		if (!pl.equals(mypl)) {
diff --git a/Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/api/db/VTSessionContentHandler.java b/Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/api/db/VTSessionContentHandler.java
index 7f7be2ff35..a65b77307f 100644
--- a/Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/api/db/VTSessionContentHandler.java
+++ b/Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/api/db/VTSessionContentHandler.java
@@ -21,12 +21,13 @@ import javax.swing.Icon;
 
 import db.DBHandle;
 import db.buffers.BufferFile;
+import db.buffers.LocalManagedBufferFile;
 import generic.theme.GIcon;
-import ghidra.framework.data.DBContentHandler;
-import ghidra.framework.data.DomainObjectMergeManager;
+import ghidra.framework.data.*;
 import ghidra.framework.model.ChangeSet;
 import ghidra.framework.model.DomainObject;
 import ghidra.framework.store.*;
+import ghidra.framework.store.local.LocalDatabaseItem;
 import ghidra.util.*;
 import ghidra.util.exception.CancelledException;
 import ghidra.util.exception.VersionException;
@@ -168,4 +169,20 @@ public class VTSessionContentHandler extends DBContentHandler<VTSessionDB> {
 		return false;
 	}
 
+	@Override
+	public boolean canResetDBSourceFile() {
+		return true;
+	}
+
+	@Override
+	public void resetDBSourceFile(FolderItem item, DomainObjectAdapterDB domainObj)
+			throws IOException {
+		if (!(item instanceof LocalDatabaseItem dbItem) ||
+			!(domainObj instanceof VTSessionDB vtSession)) {
+			throw new IllegalArgumentException("LocalDatabaseItem and VTSessionDB required");
+		}
+		LocalManagedBufferFile bf = dbItem.openForUpdate(FolderItem.DEFAULT_CHECKOUT_ID);
+		vtSession.getDBHandle().setDBVersionedSourceFile(bf);
+	}
+
 }
diff --git a/Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/gui/plugin/VTControllerImpl.java b/Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/gui/plugin/VTControllerImpl.java
index 8a3deba1dd..2473ee06f8 100644
--- a/Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/gui/plugin/VTControllerImpl.java
+++ b/Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/gui/plugin/VTControllerImpl.java
@@ -28,7 +28,6 @@ import ghidra.app.plugin.core.colorizer.ColorizingService;
 import ghidra.feature.vt.api.db.VTAssociationDB;
 import ghidra.feature.vt.api.db.VTSessionDB;
 import ghidra.feature.vt.api.main.*;
-import ghidra.feature.vt.api.util.VTSessionFileUtil;
 import ghidra.feature.vt.gui.duallisting.VTListingContext;
 import ghidra.feature.vt.gui.provider.markuptable.VTMarkupItemContext;
 import ghidra.feature.vt.gui.task.SaveTask;
@@ -69,7 +68,6 @@ public class VTControllerImpl
 
 	private ToolOptions vtOptions;
 	private MatchInfo currentMatchInfo;
-	private MyFolderListener folderListener;
 
 	public VTControllerImpl(VTPlugin plugin) {
 		this.plugin = plugin;
@@ -77,11 +75,6 @@ public class VTControllerImpl
 		matchInfoFactory = new MatchInfoFactory();
 		vtOptions = plugin.getTool().getOptions(VERSION_TRACKING_OPTIONS_NAME);
 		vtOptions.addOptionsChangeListener(this);
-		folderListener = new MyFolderListener();
-		plugin.getTool()
-				.getProject()
-				.getProjectData()
-				.addDomainFolderChangeListener(folderListener);
 	}
 
 	@Override
@@ -763,82 +756,6 @@ public class VTControllerImpl
 // Inner Classes
 //==================================================================================================
 
-	private void updateProgram(DomainFile file, boolean isSource) {
-
-		String type = isSource ? "Source" : "Destination";
-		Program newProgram;
-		try {
-			newProgram = (Program) file.getDomainObject(this, false, false, TaskMonitor.DUMMY);
-		}
-		catch (Exception e) {
-			Msg.showError(this, getParentComponent(),
-				"Error opening VT " + type + " Program: " + file, e);
-			return;
-		}
-
-		if (isSource) {
-			session.updateSourceProgram(newProgram);
-		}
-		else {
-			session.updateDestinationProgram(newProgram);
-		}
-
-//		List<DomainObjectChangeRecord> events = new ArrayList<DomainObjectChangeRecord>();
-//		events.add(new DomainObjectChangeRecord(DomainObjectEvent.RESTORED));
-//		domainObjectChanged(new DomainObjectChangedEvent(newProgram, events));
-		matchInfoFactory.clearCache();
-		fireSessionChanged();
-	}
-
-	private class MyFolderListener extends DomainFolderListenerAdapter {
-
-		@Override
-		public void domainFileObjectReplaced(DomainFile file, DomainObject oldObject) {
-
-			if (session == null) {
-				return;
-			}
-
-			if (session.getSourceProgram() == oldObject) {
-				updateProgram(file, true);
-				return;
-			}
-
-			String type;
-			if (session == oldObject) {
-				type = "VT Session";
-			}
-			else if (session.getDestinationProgram() == oldObject) {
-				if (VTSessionFileUtil.canUpdate(file)) {
-					updateProgram(file, false);
-					return;
-				}
-				type = "Destination Program";
-			}
-			else {
-				return;
-			}
-
-			// Session or destination program can no longer be saved to project so we
-			// have no choice but to close session.
-
-			// Since we are already in the Swing thread we need to delay closing so we do
-			// not continue to block the Swing thread and the checkin which is in progress.
-			// This allows the DomainFile checkin to complete its processing first.
-			SwingUtilities.invokeLater(() -> {
-
-				Msg.showInfo(this, plugin.getTool().getToolFrame(), "Closing VT Session",
-					type + " checkin has forced session close.\n" +
-						"You will be prompted to save any other changes if needed, after which\n" +
-						"you may reopen the VT Session.");
-
-				closeVersionTrackingSession();
-
-				// NOTE: a future convenience could be added to attempt reopening of session
-			});
-		}
-	}
-
 	private class OpenSessionTask extends Task {
 
 		private final VTSession newSession;
diff --git a/Ghidra/Framework/DB/src/main/java/db/DBHandle.java b/Ghidra/Framework/DB/src/main/java/db/DBHandle.java
index 98909d6ee4..1f00f89d95 100644
--- a/Ghidra/Framework/DB/src/main/java/db/DBHandle.java
+++ b/Ghidra/Framework/DB/src/main/java/db/DBHandle.java
@@ -18,7 +18,6 @@ package db;
 import java.io.File;
 import java.io.IOException;
 import java.util.Hashtable;
-import java.util.Iterator;
 
 import db.buffers.*;
 import db.util.ErrorHandler;
@@ -439,8 +438,7 @@ public class DBHandle {
 	 * @throws IllegalStateException if transaction is already active or this {@link DBHandle} has 
 	 * already been closed.
 	 */
-	public Transaction openTransaction(ErrorHandler errorHandler)
-			throws IllegalStateException {
+	public Transaction openTransaction(ErrorHandler errorHandler) throws IllegalStateException {
 		return new Transaction() {
 
 			long txId = startTransaction();
@@ -542,6 +540,33 @@ public class DBHandle {
 		return (bufferMgr != null && !bufferMgr.atCheckpoint());
 	}
 
+	/**
+	 * Set the DB source buffer file with a newer local buffer file version.
+	 * Intended for use following a merge or commit operation only where a local checkout has been
+	 * retained.
+	 * @param versionedSourceBufferFile updated local DB source buffer file opened for versioning 
+	 * update (NOTE: file itself is read-only).  File must be an instance of 
+	 * {@link LocalManagedBufferFile}.
+	 * @throws IOException if an IO error occurs
+	 */
+	public void setDBVersionedSourceFile(BufferFile versionedSourceBufferFile) throws IOException {
+		if (!(versionedSourceBufferFile instanceof LocalManagedBufferFile bf) ||
+			!versionedSourceBufferFile.isReadOnly()) {
+			throw new IllegalArgumentException(
+				"Requires local versioned buffer file opened for versioning update");
+		}
+		synchronized (this) {
+			if (isTransactionActive()) {
+				throw new IOException("transaction is active");
+			}
+			bufferMgr.clearRecoveryFiles();
+			bufferMgr.setDBVersionedSourceFile(bf);
+			++checkpointNum;
+			reloadTables();
+		}
+		notifyDbRestored();
+	}
+
 	/**
 	 * Terminate current transaction.  If commit is false a rollback may occur followed by
 	 * {@link DBListener#dbRestored(DBHandle)} notification to listeners.  This method is very 
@@ -1022,10 +1047,9 @@ public class DBHandle {
 	public Table[] getTables() {
 		Table[] t = new Table[tables.size()];
 
-		Iterator<Table> it = tables.values().iterator();
 		int i = 0;
-		while (it.hasNext()) {
-			t[i++] = it.next();
+		for (Table element : tables.values()) {
+			t[i++] = element;
 		}
 		return t;
 	}
@@ -1050,8 +1074,7 @@ public class DBHandle {
 	 * @return new table instance
 	 * @throws IOException if IO error occurs during table creation
 	 */
-	public Table createTable(String name, Schema schema, int[] indexedColumns)
-			throws IOException {
+	public Table createTable(String name, Schema schema, int[] indexedColumns) throws IOException {
 		Table table;
 		synchronized (this) {
 			if (tables.containsKey(name)) {
diff --git a/Ghidra/Framework/DB/src/main/java/db/buffers/BufferMgr.java b/Ghidra/Framework/DB/src/main/java/db/buffers/BufferMgr.java
index 978131edd5..88eda4b1ba 100644
--- a/Ghidra/Framework/DB/src/main/java/db/buffers/BufferMgr.java
+++ b/Ghidra/Framework/DB/src/main/java/db/buffers/BufferMgr.java
@@ -223,6 +223,22 @@ public class BufferMgr {
 			approxCacheSize < MINIMUM_CACHE_SIZE ? MINIMUM_CACHE_SIZE : approxCacheSize;
 		maxCacheSize = (int) (approxCacheSize / bufferSize);
 
+		// Setup baseline - checkpoint 0
+		startCheckpoint();
+		baselineCheckpointHead = currentCheckpointHead;
+		currentCheckpointHead = null;
+
+		initializeCache();
+
+		addInstance(this);
+	}
+
+	private void initializeCache() throws IOException {
+
+		if (cacheFile != null) {
+			cacheFile.delete();
+		}
+
 		// Setup memory cache list
 		cacheHead = new BufferNode(HEAD, -1);
 		cacheTail = new BufferNode(TAIL, -1);
@@ -234,11 +250,6 @@ public class BufferMgr {
 
 		cacheIndexProvider = new IndexProvider();
 
-		// Setup baseline - checkpoint 0
-		startCheckpoint();
-		baselineCheckpointHead = currentCheckpointHead;
-		currentCheckpointHead = null;
-
 		// Copy file parameters into cache file
 		if (sourceFile != null) {
 			String[] parmNames = sourceFile.getParameterNames();
@@ -247,8 +258,6 @@ public class BufferMgr {
 			}
 		}
 
-		addInstance(this);
-
 		if (alwaysPreCache) {
 			startPreCacheIfNeeded();
 		}
@@ -417,9 +426,7 @@ public class BufferMgr {
 
 				// Dispose all buffer nodes - speeds up garbage collection
 				if (checkpointHeads != null) {
-					Iterator<BufferNode> iter = checkpointHeads.iterator();
-					while (iter.hasNext()) {
-						BufferNode node = iter.next();
+					for (BufferNode node : checkpointHeads) {
 						while (node != null) {
 							BufferNode next = node.nextInCheckpoint;
 							node.buffer = null;
@@ -435,9 +442,7 @@ public class BufferMgr {
 					checkpointHeads = null;
 				}
 				if (redoCheckpointHeads != null) {
-					Iterator<BufferNode> iter = redoCheckpointHeads.iterator();
-					while (iter.hasNext()) {
-						BufferNode node = iter.next();
+					for (BufferNode node : redoCheckpointHeads) {
 						while (node != null) {
 							BufferNode next = node.nextInCheckpoint;
 							node.buffer = null;
@@ -702,24 +707,7 @@ public class BufferMgr {
 			return; // only pre-cache remote buffer files
 		}
 		synchronized (preCacheLock) {
-			preCacheThread = new Thread(() -> {
-				try {
-					preCacheSourceFile();
-				}
-				catch (InterruptedIOException e) {
-					// ignore
-				}
-				catch (IOException e) {
-					Msg.error(BufferMgr.this, "pre-cache failure: " + e.getMessage(), e);
-				}
-				finally {
-					synchronized (preCacheLock) {
-						preCacheStatus = PreCacheStatus.STOPPED;
-						preCacheThread = null;
-						preCacheLock.notifyAll();
-					}
-				}
-			});
+			preCacheThread = new Thread(() -> preCacheSourceFile());
 			preCacheThread.setName("Pre-Cache");
 			preCacheThread.setPriority(Thread.MIN_PRIORITY);
 			preCacheThread.start();
@@ -731,23 +719,38 @@ public class BufferMgr {
 	 * Pre-cache source file into cache file.  This is intended to be run in a
 	 * dedicated thread when the source file is remote.
 	 */
-	private void preCacheSourceFile() throws IOException {
-		if (!(sourceFile instanceof BufferFileAdapter)) {
-			throw new UnsupportedOperationException("unsupported use of preCacheSourceFile");
-		}
-		Msg.trace(BufferMgr.this, "Pre-cache started...");
-		int cacheCount = 0;
-		BufferFileAdapter sourceAdapter = (BufferFileAdapter) sourceFile;
-		try (InputBlockStream inputBlockStream = sourceAdapter.getInputBlockStream()) {
-			BufferFileBlock block;
-			while (!Thread.interrupted() && (block = inputBlockStream.readBlock()) != null) {
-				DataBuffer buf = LocalBufferFile.getDataBuffer(block);
-				if (buf != null && !buf.isEmpty() && preCacheBuffer(buf)) { // skip head block and empty blocks
-					++cacheCount;
-				}
+	private void preCacheSourceFile() {
+		try {
+			if (!(sourceFile instanceof BufferFileAdapter)) {
+				throw new UnsupportedOperationException("unsupported use of preCacheSourceFile");
+			}
+			Msg.trace(BufferMgr.this, "Pre-cache started...");
+			int cacheCount = 0;
+			BufferFileAdapter sourceAdapter = (BufferFileAdapter) sourceFile;
+			try (InputBlockStream inputBlockStream = sourceAdapter.getInputBlockStream()) {
+				BufferFileBlock block;
+				while (!Thread.interrupted() && (block = inputBlockStream.readBlock()) != null) {
+					DataBuffer buf = LocalBufferFile.getDataBuffer(block);
+					if (buf != null && !buf.isEmpty() && preCacheBuffer(buf)) { // skip head block and empty blocks
+						++cacheCount;
+					}
+				}
+				Msg.trace(BufferMgr.this, "Pre-cache added " + cacheCount + " of " +
+					sourceFile.getIndexCount() + " buffers to cache");
+			}
+		}
+		catch (InterruptedIOException e) {
+			// ignore
+		}
+		catch (IOException e) {
+			Msg.error(BufferMgr.this, "pre-cache failure: " + e.getMessage(), e);
+		}
+		finally {
+			synchronized (preCacheLock) {
+				preCacheStatus = PreCacheStatus.STOPPED;
+				preCacheThread = null;
+				preCacheLock.notifyAll();
 			}
-			Msg.trace(BufferMgr.this, "Pre-cache added " + cacheCount + " of " +
-				sourceFile.getIndexCount() + " buffers to cache");
 		}
 	}
 
@@ -1744,6 +1747,51 @@ public class BufferMgr {
 		return false;
 	}
 
+	/**
+	 * Set the source buffer file with a newer local buffer file version.
+	 * Intended for use following a merge or commit operation only where a local checkout has been
+	 * retained.
+	 * @param versionedSourceBufferFile updated local source buffer file opened for versioning 
+	 * update (NOTE: file itself is read-only).
+	 * @throws IOException if an IO error occurs
+	 */
+	public void setDBVersionedSourceFile(LocalManagedBufferFile versionedSourceBufferFile)
+			throws IOException {
+
+		synchronized (snapshotLock) {
+			synchronized (this) {
+				if (!(sourceFile instanceof LocalManagedBufferFile)) {
+					throw new UnsupportedOperationException(getClass().getSimpleName() +
+						".setDBSourceFile not allowed: " + sourceFile.getClass());
+				}
+				if (bufferSize != sourceFile.getBufferSize()) {
+					throw new IllegalArgumentException("Buffer size mismatch");
+				}
+
+				if (corruptedState) {
+					throw new IOException("Corrupted BufferMgr state");
+				}
+
+				if (lockCount != 0) {
+					throw new IOException("Attempted checkout update while buffers are locked");
+				}
+
+				stopPreCache();
+
+				clearCheckpoints();
+
+				doSetSourceFile(versionedSourceBufferFile);
+
+				// re-initialize cached file data
+				int cnt = sourceFile.getIndexCount();
+				indexProvider = new IndexProvider(cnt, sourceFile.getFreeIndexes());
+				bufferTable = new ObjectArray(cnt + INITIAL_BUFFER_TABLE_SIZE);
+
+				initializeCache();
+			}
+		}
+	}
+
 	/**
 	 * Save the current set of buffers to a new version of the source buffer file.
 	 * If the buffer manager was not instantiated with a source file an
@@ -1825,7 +1873,7 @@ public class BufferMgr {
 					monitor.setCancelEnabled(oldCancelState & !monitor.isCancelled());
 				}
 
-				setSourceFile(outFile);
+				doSetSourceFile(outFile);
 			}
 		}
 	}
@@ -1881,7 +1929,7 @@ public class BufferMgr {
 					monitor.setCancelEnabled(true);
 				}
 				if (associateWithNewFile) {
-					setSourceFile(outFile);
+					doSetSourceFile(outFile);
 				}
 			}
 		}
@@ -1965,7 +2013,7 @@ public class BufferMgr {
 		}
 	}
 
-	private void setSourceFile(BufferFile newFile) {
+	private void doSetSourceFile(BufferFile newFile) {
 
 		// Close buffer file
 		if (sourceFile != null) {
diff --git a/Ghidra/Framework/DB/src/main/java/db/buffers/LocalManagedBufferFile.java b/Ghidra/Framework/DB/src/main/java/db/buffers/LocalManagedBufferFile.java
index 7ce4ed857e..376e9c3cd1 100644
--- a/Ghidra/Framework/DB/src/main/java/db/buffers/LocalManagedBufferFile.java
+++ b/Ghidra/Framework/DB/src/main/java/db/buffers/LocalManagedBufferFile.java
@@ -157,7 +157,6 @@ public class LocalManagedBufferFile extends LocalBufferFile implements ManagedBu
 	 * <code>preSaveThread</code> corresponds to the PreSaveTask which creates the 
 	 * preSaveFile when this buffer file is updateable.
 	 */
-	//private Thread preSaveThread;
 	private PreSaveTask preSaveTask;
 
 	/**
@@ -228,8 +227,8 @@ public class LocalManagedBufferFile extends LocalBufferFile implements ManagedBu
 		setFreeIndexes(versionFileHandler.getFreeIndexList());
 		String[] names = versionFileHandler.getOldParameterNames();
 		clearParameters();
-		for (int i = 0; i < names.length; i++) {
-			setParameter(names[i], versionFileHandler.getOldParameter(names[i]));
+		for (String name : names) {
+			setParameter(name, versionFileHandler.getOldParameter(name));
 		}
 	}
 
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/ContentHandler.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/ContentHandler.java
index f8406044b0..78dda0a7de 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/ContentHandler.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/ContentHandler.java
@@ -17,6 +17,7 @@ package ghidra.framework.data;
 
 import java.io.IOException;
 
+import javax.help.UnsupportedOperationException;
 import javax.swing.Icon;
 
 import ghidra.framework.model.*;
@@ -83,9 +84,8 @@ public interface ContentHandler<T extends DomainObjectAdapter> extends Extension
 	 * @throws VersionException if unable to handle file content due to version 
 	 * difference which could not be handled.
 	 */
-	T getImmutableObject(FolderItem item, Object consumer, int version,
-			int minChangeVersion, TaskMonitor monitor)
-			throws IOException, CancelledException, VersionException;
+	T getImmutableObject(FolderItem item, Object consumer, int version, int minChangeVersion,
+			TaskMonitor monitor) throws IOException, CancelledException, VersionException;
 
 	/**
 	 * Open a folder item for read-only use.  While changes are permitted on the
@@ -104,9 +104,8 @@ public interface ContentHandler<T extends DomainObjectAdapter> extends Extension
 	 * @throws VersionException if unable to handle file content due to version 
 	 * difference which could not be handled.
 	 */
-	T getReadOnlyObject(FolderItem item, int version, boolean okToUpgrade,
-			Object consumer, TaskMonitor monitor)
-			throws IOException, VersionException, CancelledException;
+	T getReadOnlyObject(FolderItem item, int version, boolean okToUpgrade, Object consumer,
+			TaskMonitor monitor) throws IOException, VersionException, CancelledException;
 
 	/**
 	 * Open a folder item for update.  Changes made to the returned object may be
@@ -127,8 +126,8 @@ public interface ContentHandler<T extends DomainObjectAdapter> extends Extension
 	 * @throws VersionException if unable to handle file content due to version 
 	 * difference which could not be handled.
 	 */
-	T getDomainObject(FolderItem item, FileSystem userfs, long checkoutId,
-			boolean okToUpgrade, boolean okToRecover, Object consumer, TaskMonitor monitor)
+	T getDomainObject(FolderItem item, FileSystem userfs, long checkoutId, boolean okToUpgrade,
+			boolean okToRecover, Object consumer, TaskMonitor monitor)
 			throws IOException, CancelledException, VersionException;
 
 	/**
@@ -204,4 +203,47 @@ public interface ContentHandler<T extends DomainObjectAdapter> extends Extension
 		return null;
 	}
 
+	/**
+	 * Determine if this content handler supports the use of 
+	 * {@link #resetDBSourceFile(FolderItem, DomainObjectAdapterDB)} .
+	 * <p>
+	 * A versioned {@link DomainObjectAdapterDB domain object} open for update may have its 
+	 * underlying database reset to the latest buffer file version:
+	 * <ol>
+	 * <li>The {@link #resetDBSourceFile(FolderItem, DomainObjectAdapterDB)} method is
+	 * invoked (synchronized on filesystem) to reset the underlying database source file and
+	 * and any corresponding change sets held by the specified domain object to the latest 
+	 * version,</li>
+	 * <li>afterwhich the caller must {@link DomainObjectAdapter#invalidate() invalidate} the domain 
+	 * object instance which will clear all caches and generate a {@link DomainObjectEvent#RESTORED} 
+	 * event.</li>
+	 *  </ol>
+	 * @return true if this content handler supports DB source file replacement, else false
+	 */
+	public default boolean canResetDBSourceFile() {
+		return false;
+	}
+
+	/**
+	 * Reset the database for the specified domain object to its latest buffer file version.
+	 * It is very important that the specified folder item matches the item which was used to 
+	 * originally open the specified domain object. This method should be invoked with a 
+	 * filesystem lock.
+	 * <p>
+	 * Following the invocation of this method, the specified domain object should be 
+	 * {@link DomainObjectAdapter#invalidate() invalidated} without a filesystem lock.
+	 * 
+	 * @param item local versioned database folder item currently checked-out. An error will be
+	 * thrown if not an instanceof LocalDatabaseItem.  This should always be the case for an item
+	 * which has just processed a versioning action with a retained checkout (e.g., checkin,
+	 * merge, add-to-version-control).
+	 * @param domainObj domain object which is currently open for update
+	 * @throws IOException if an IO error occurs
+	 * @throws IllegalArgumentException if invalid or unsupported arguments are provided
+	 */
+	public default void resetDBSourceFile(FolderItem item, DomainObjectAdapterDB domainObj)
+			throws IOException {
+		throw new UnsupportedOperationException();
+	}
+
 }
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DBContentHandler.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DBContentHandler.java
index 4b62da8926..3136f8cd2c 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DBContentHandler.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DBContentHandler.java
@@ -17,6 +17,8 @@ package ghidra.framework.data;
 
 import java.io.IOException;
 
+import javax.help.UnsupportedOperationException;
+
 import db.DBHandle;
 import db.buffers.ManagedBufferFile;
 import ghidra.framework.store.*;
@@ -55,9 +57,8 @@ public abstract class DBContentHandler<T extends DomainObjectAdapterDB>
 			FileSystem fs, String path, String name, TaskMonitor monitor)
 			throws InvalidNameException, CancelledException, IOException {
 		DBHandle dbh = domainObj.getDBHandle();
-		ManagedBufferFile bf =
-			fs.createDatabase(path, name, FileIDFactory.createFileID(), contentType,
-				dbh.getBufferSize(), SystemUtilities.getUserName(), null);
+		ManagedBufferFile bf = fs.createDatabase(path, name, FileIDFactory.createFileID(),
+			contentType, dbh.getBufferSize(), SystemUtilities.getUserName(), null);
 		long checkoutId = bf.getCheckinID();  // item remains checked-out after saveAs
 		boolean success = false;
 		try {
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DefaultCheckinHandler.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DefaultCheckinHandler.java
index c985b8b963..4f89e1c0c8 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DefaultCheckinHandler.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DefaultCheckinHandler.java
@@ -21,7 +21,7 @@ import ghidra.util.exception.CancelledException;
 /**
  * <code>DefaultCheckinHandler</code> provides a simple
  * check-in handler for use with 
- * {@link DomainFile#checkin(CheckinHandler, boolean, ghidra.util.task.TaskMonitor)}
+ * {@link DomainFile#checkin(CheckinHandler, ghidra.util.task.TaskMonitor)}
  */
 public class DefaultCheckinHandler implements CheckinHandler {
 	
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFileIndex.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFileIndex.java
index a4052a91f6..3965f0411f 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFileIndex.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFileIndex.java
@@ -181,57 +181,31 @@ class DomainFileIndex implements DomainFolderChangeListener {
 		return null;
 	}
 
+	@Override
 	public void domainFileAdded(DomainFile file) {
 		updateFileEntry((GhidraFile) file);
 	}
 
+	@Override
 	public void domainFileMoved(DomainFile file, DomainFolder oldParent, String oldName) {
 		updateFileEntry((GhidraFile) file);
 	}
 
-	public void domainFileObjectClosed(DomainFile file, DomainObject object) {
-		// no-op
-	}
-
-	public void domainFileObjectOpenedForUpdate(DomainFile file, DomainObject object) {
-		// no-op
-	}
-
-	public void domainFileObjectReplaced(DomainFile file, DomainObject oldObject) {
-		// no-op
-	}
-
+	@Override
 	public void domainFileRemoved(DomainFolder parent, String name, String fileID) {
 		fileIdToPathIndex.remove(fileID);
 	}
 
+	@Override
 	public void domainFileRenamed(DomainFile file, String oldName) {
 		updateFileEntry((GhidraFile) file);
 	}
 
+	@Override
 	public void domainFileStatusChanged(DomainFile file, boolean fileIDset) {
 		if (fileIDset) {
 			updateFileEntry((GhidraFile) file);
 		}
 	}
 
-	public void domainFolderAdded(DomainFolder folder) {
-		// no-op
-	}
-
-	public void domainFolderMoved(DomainFolder folder, DomainFolder oldParent) {
-		// no-op
-	}
-
-	public void domainFolderRemoved(DomainFolder parent, String name) {
-		// no-op
-	}
-
-	public void domainFolderRenamed(DomainFolder folder, String oldName) {
-		// no-op
-	}
-
-	public void domainFolderSetActive(DomainFolder folder) {
-		// no-op
-	}
 }
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFileProxy.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFileProxy.java
index bbaff1ff36..3c558d0d20 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFileProxy.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFileProxy.java
@@ -398,7 +398,7 @@ public class DomainFileProxy implements DomainFile {
 	}
 
 	@Override
-	public void checkin(CheckinHandler checkinHandler, boolean okToUpgrade, TaskMonitor monitor)
+	public void checkin(CheckinHandler checkinHandler, TaskMonitor monitor)
 			throws IOException, VersionException, CancelledException {
 		throw new UnsupportedOperationException("Repository operations not supported");
 	}
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFolderChangeListenerList.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFolderChangeListenerList.java
index af523cc8be..a2cc74cf27 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFolderChangeListenerList.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFolderChangeListenerList.java
@@ -26,8 +26,7 @@ class DomainFolderChangeListenerList implements DomainFolderChangeListener {
 	private DomainFileIndex fileIndex;
 
 	/** CopyOnWriteArrayList prevents the need for synchronization */
-	private List<DomainFolderChangeListener> list =
-		new CopyOnWriteArrayList<>();
+	private List<DomainFolderChangeListener> list = new CopyOnWriteArrayList<>();
 
 	DomainFolderChangeListenerList(DomainFileIndex fileIndex) {
 		this.fileIndex = fileIndex;
@@ -199,19 +198,6 @@ class DomainFolderChangeListenerList implements DomainFolderChangeListener {
 		});
 	}
 
-	@Override
-	public void domainFileObjectReplaced(final DomainFile file, final DomainObject oldObject) {
-		fileIndex.domainFileObjectReplaced(file, oldObject);
-		if (list.isEmpty()) {
-			return;
-		}
-		Swing.runNow(() -> {
-			for (DomainFolderChangeListener listener : list) {
-				listener.domainFileObjectReplaced(file, oldObject);
-			}
-		});
-	}
-
 	public void clearAll() {
 		list.clear();
 	}
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainObjectAdapter.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainObjectAdapter.java
index b3d0bd6a42..5e9aad26f8 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainObjectAdapter.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainObjectAdapter.java
@@ -81,8 +81,8 @@ public abstract class DomainObjectAdapter implements DomainObject {
 	 * with consumer.
 	 *
 	 * @param name name of the object
-	 * @param timeInterval the time (in milliseconds) to wait before the event queue is flushed. If
-	 *            a new event comes in before the time expires, the timer is reset.
+	 * @param timeInterval the time (in milliseconds) to wait before the event queue is flushed. 
+	 * 			If a new event comes in before the time expires the timer is reset.
 	 * @param consumer the object that created this domain object
 	 */
 	protected DomainObjectAdapter(String name, int timeInterval, Object consumer) {
@@ -98,6 +98,15 @@ public abstract class DomainObjectAdapter implements DomainObject {
 		}
 	}
 
+	/**
+	 * Invalidates any caching in a program and generate a {@link DomainObjectEvent#RESTORED}
+	 * event. 
+	 * NOTE: Over-using this method can adversely affect system performance.
+	 */
+	public void invalidate() {
+		fireEvent(new DomainObjectChangeRecord(DomainObjectEvent.RESTORED));
+	}
+
 	@Override
 	public void release(Object consumer) {
 		synchronized (consumers) {
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainObjectAdapterDB.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainObjectAdapterDB.java
index ec193d83e0..0205d0e7f8 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainObjectAdapterDB.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainObjectAdapterDB.java
@@ -37,32 +37,6 @@ import ghidra.util.task.TaskMonitor;
  * concept of starting a transaction before a change is made to the
  * domain object and ending the transaction. The transaction allows for
  * undo/redo changes.
- *
- * The implementation class must also satisfy the following requirements:
- * <pre>
- *
- * 1. The following constructor signature must be implemented:
- *
- * 		 **
- *		 * Constructs new Domain Object
- *		 * @param dbh a handle to an open domain object database.
- *		 * @param openMode one of:
- *		 * 		READ_ONLY: the original database will not be modified
- *		 * 		UPDATE: the database can be written to.
- *		 * 		UPGRADE: the database is upgraded to the latest schema as it is opened.
- *		 * @param monitor TaskMonitor that allows the open to be cancelled.
- *	     * @param consumer the object that keeping the program open.
- *		 *
- *		 * @throws IOException if an error accessing the database occurs.
- *		 * @throws VersionException if database version does not match implementation. UPGRADE may be possible.
- *		 **
- *		 public DomainObjectAdapterDB(DBHandle dbh, int openMode, TaskMonitor monitor, Object consumer) throws IOException, VersionException
- *
- * 2. The following static field must be provided:
- *
- * 		 public static final String CONTENT_TYPE
- *
- * </pre>
  */
 public abstract class DomainObjectAdapterDB extends DomainObjectAdapter
 		implements ErrorHandler, DBConstants {
@@ -100,12 +74,10 @@ public abstract class DomainObjectAdapterDB extends DomainObjectAdapter
 
 	/**
 	 * Construct a new DomainObjectAdapterDB object.
-	 * If construction of this object fails, be sure to release with consumer
 	 * @param dbh database handle
 	 * @param name name of the domain object
-	 * @param timeInterval the time (in milliseconds) to wait before the
-	 * event queue is flushed.  If a new event comes in before the time expires,
-	 * the timer is reset.
+	 * @param timeInterval the time (in milliseconds) to wait before the event queue is flushed.  
+	 * 			If a new event comes in before the time expires the timer is reset.
 	 * @param consumer the object that created this domain object
 	 */
 	protected DomainObjectAdapterDB(DBHandle dbh, String name, int timeInterval, Object consumer) {
@@ -129,6 +101,7 @@ public abstract class DomainObjectAdapterDB extends DomainObjectAdapter
 	 * prior to closing a transaction.
 	 */
 	public void flushWriteCache() {
+		// do nothing
 	}
 
 	/**
@@ -137,6 +110,7 @@ public abstract class DomainObjectAdapterDB extends DomainObjectAdapter
 	 * prior to aborting a transaction.
 	 */
 	public void invalidateWriteCache() {
+		// do nothing
 	}
 
 	/**
@@ -491,6 +465,12 @@ public abstract class DomainObjectAdapterDB extends DomainObjectAdapter
 		transactionMgr.clearUndo(notifyListeners);
 	}
 
+	@Override
+	public void invalidate() {
+		clearCache(false);
+		super.invalidate();
+	}
+
 	protected void clearCache(boolean all) {
 		options.clearCache();
 	}
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFile.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFile.java
index 21c1143b39..398c651354 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFile.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFile.java
@@ -382,10 +382,11 @@ public class GhidraFile implements DomainFile {
 	@Override
 	public boolean canAddToRepository() {
 		try {
-			return getFileData().canAddToRepository();
+			getFileData().checkCanAddToRepository();
+			return true;
 		}
 		catch (IOException e) {
-			fileError(e);
+			// ignore
 		}
 		return false;
 	}
@@ -473,10 +474,9 @@ public class GhidraFile implements DomainFile {
 	}
 
 	@Override
-	public void checkin(CheckinHandler checkinHandler, boolean okToUpgrade, TaskMonitor monitor)
+	public void checkin(CheckinHandler checkinHandler, TaskMonitor monitor)
 			throws IOException, VersionException, CancelledException {
-		getFileData().checkin(checkinHandler, okToUpgrade,
-			monitor != null ? monitor : TaskMonitor.DUMMY);
+		getFileData().checkin(checkinHandler, monitor != null ? monitor : TaskMonitor.DUMMY);
 	}
 
 	@Override
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFileData.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFileData.java
index 2f06823cf5..811f3ccfdc 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFileData.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFileData.java
@@ -436,9 +436,8 @@ public class GhidraFileData {
 	ChangeSet getChangesByOthersSinceCheckout() throws VersionException, IOException {
 		synchronized (fileSystem) {
 			if (versionedFolderItem != null && folderItem != null && folderItem.isCheckedOut()) {
-				ContentHandler<?> ch = getContentHandler();
-				return ch.getChangeSet(versionedFolderItem, folderItem.getCheckoutVersion(),
-					versionedFolderItem.getCurrentVersion());
+				return getContentHandler().getChangeSet(versionedFolderItem,
+					folderItem.getCheckoutVersion(), versionedFolderItem.getCurrentVersion());
 			}
 			return null;
 		}
@@ -478,6 +477,12 @@ public class GhidraFileData {
 	 */
 	DomainObject getDomainObject(Object consumer, boolean okToUpgrade, boolean okToRecover,
 			TaskMonitor monitor) throws VersionException, IOException, CancelledException {
+
+		// Don't allow this call while versioning operation is on-going
+		if (busy.get()) {
+			throw new FileInUseException("Cannot open during versioning operation");
+		}
+
 		FolderItem myFolderItem;
 		DomainObjectAdapter domainObj = null;
 		synchronized (fileSystem) {
@@ -494,9 +499,9 @@ public class GhidraFileData {
 					return domainObj;
 				}
 			}
-			ContentHandler<?> ch = getContentHandler();
+			ContentHandler<?> contentHandler = getContentHandler();
 			if (folderItem == null) {
-				DomainObjectAdapter doa = ch.getReadOnlyObject(versionedFolderItem,
+				DomainObjectAdapter doa = contentHandler.getReadOnlyObject(versionedFolderItem,
 					DomainFile.DEFAULT_VERSION, true, consumer, monitor);
 				doa.setChanged(false);
 				DomainFileProxy proxy = new DomainFileProxy(name, parent.getPathname(), doa,
@@ -506,7 +511,7 @@ public class GhidraFileData {
 			}
 			myFolderItem = folderItem;
 
-			domainObj = ch.getDomainObject(myFolderItem, parent.getUserFileSystem(),
+			domainObj = contentHandler.getDomainObject(myFolderItem, parent.getUserFileSystem(),
 				FolderItem.DEFAULT_CHECKOUT_ID, okToUpgrade, okToRecover, consumer, monitor);
 			projectData.setDomainObject(getPathname(), domainObj);
 
@@ -567,8 +572,8 @@ public class GhidraFileData {
 			FolderItem item =
 				(folderItem != null && version == DomainFile.DEFAULT_VERSION) ? folderItem
 						: versionedFolderItem;
-			ContentHandler<?> ch = getContentHandler();
-			DomainObjectAdapter doa = ch.getReadOnlyObject(item, version, true, consumer, monitor);
+			DomainObjectAdapter doa =
+				getContentHandler().getReadOnlyObject(item, version, true, consumer, monitor);
 			doa.setChanged(false);
 
 			// Notify file manager of in-use domain object.
@@ -606,13 +611,14 @@ public class GhidraFileData {
 			throws VersionException, IOException, CancelledException {
 		synchronized (fileSystem) {
 			DomainObjectAdapter obj = null;
-			ContentHandler<?> ch = getContentHandler();
+			ContentHandler<?> contentHandler = getContentHandler();
 			if (versionedFolderItem == null ||
 				(version == DomainFile.DEFAULT_VERSION && folderItem != null) || isHijacked()) {
-				obj = ch.getImmutableObject(folderItem, consumer, version, -1, monitor);
+				obj = contentHandler.getImmutableObject(folderItem, consumer, version, -1, monitor);
 			}
 			else {
-				obj = ch.getImmutableObject(versionedFolderItem, consumer, version, -1, monitor);
+				obj = contentHandler.getImmutableObject(versionedFolderItem, consumer, version, -1,
+					monitor);
 			}
 
 			// Notify file manager of in-use domain object.
@@ -870,33 +876,6 @@ public class GhidraFileData {
 		}
 	}
 
-	/**
-	 * Returns true if this private file may be added to the associated repository.
-	 * @return true if can add to the repository
-	 */
-	boolean canAddToRepository() {
-		synchronized (fileSystem) {
-			try {
-				if (fileSystem.isReadOnly() || versionedFileSystem.isReadOnly()) {
-					return false;
-				}
-				if (folderItem == null || versionedFolderItem != null) {
-					return false;
-				}
-				if (folderItem.isCheckedOut()) {
-					return false;
-				}
-				if (isLinkFile()) {
-					return GhidraURL.isServerRepositoryURL(LinkHandler.getURL(folderItem));
-				}
-				return !getContentHandler().isPrivateContentType();
-			}
-			catch (IOException e) {
-				return false;
-			}
-		}
-	}
-
 	/**
 	 * Returns true if this file may be checked-out from the associated repository.
 	 * User's with read-only repository access will not have checkout ability.
@@ -1021,6 +1000,32 @@ public class GhidraFileData {
 		}
 	}
 
+	/**
+	 * Perform neccessary check to ensure this file may be added to version control.
+	 * @throws IOException if any checks fail or other IO error occurs
+	 */
+	void checkCanAddToRepository() throws IOException {
+		if (!versionedFileSystem.isOnline()) {
+			throw new NotConnectedException("Not connected to repository server");
+		}
+		if (fileSystem.isReadOnly() || versionedFileSystem.isReadOnly()) {
+			throw new ReadOnlyException(
+				"versioning permitted within writeable project and repository only");
+		}
+		if (folderItem == null) {
+			throw new FileNotFoundException("File not found");
+		}
+		if (folderItem.isCheckedOut() || versionedFolderItem != null) {
+			throw new IOException("File already versioned");
+		}
+		if (isLinkFile() && !GhidraURL.isServerRepositoryURL(LinkHandler.getURL(folderItem))) {
+			throw new IOException("Local project link-file may not be versioned");
+		}
+		if (getContentHandler().isPrivateContentType()) {
+			throw new IOException("Content may not be versioned: " + getContentType());
+		}
+	}
+
 	/** 
 	 * Adds this private file to version control.
 	 * @param comment new version comment
@@ -1033,76 +1038,87 @@ public class GhidraFileData {
 	 */
 	void addToVersionControl(String comment, boolean keepCheckedOut, TaskMonitor monitor)
 			throws IOException, CancelledException {
-		DomainObjectAdapter oldDomainObj = null;
-		synchronized (fileSystem) {
-			if (!canAddToRepository()) {
-				if (fileSystem.isReadOnly() || versionedFileSystem.isReadOnly()) {
-					throw new ReadOnlyException(
-						"addToVersionControl permitted within writeable project and repository only");
-				}
-				throw new IOException("addToVersionControl not allowed for file");
-			}
+
+		checkCanAddToRepository();
+
+		if (busy.getAndSet(true)) {
+			throw new FileInUseException(name + " is busy");
+		}
+
+		DomainObjectAdapterDB inUseDomainObj = null;
+		projectData.mergeStarted();
+		try {
+			inUseDomainObj = getAndLockInUseDomainObjectForMergeUpdate("checkin");
+
 			if (isLinkFile()) {
 				keepCheckedOut = false;
 			}
-			String parentPath = parent.getPathname();
-			String user = ClientUtil.getUserName();
-			try {
-				if (folderItem instanceof DatabaseItem) {
-					DatabaseItem databaseItem = (DatabaseItem) folderItem;
-					BufferFile bufferFile = databaseItem.open();
-					try {
-						versionedFolderItem = versionedFileSystem.createDatabase(parentPath, name,
-							folderItem.getFileID(), bufferFile, comment,
-							folderItem.getContentType(), false, monitor, user);
-					}
-					finally {
-						bufferFile.dispose();
-					}
-				}
-				else if (folderItem instanceof DataFileItem) {
-					DataFileItem dataFileItem = (DataFileItem) folderItem;
-					InputStream istream = dataFileItem.getInputStream();
-					try {
-						versionedFolderItem = versionedFileSystem.createDataFile(parentPath, name,
-							istream, comment, folderItem.getContentType(), monitor);
-					}
-					finally {
-						istream.close();
-					}
-				}
-				else {
-					throw new AssertException("Unknown folder item type");
-				}
-			}
-			catch (InvalidNameException e) {
-				throw new AssertException("Unexpected error", e);
+			else if (inUseDomainObj != null && !keepCheckedOut) {
+				keepCheckedOut = true;
+				Msg.warn(this, "File currently open - must keep checked-out: " + name);
 			}
 
-			oldDomainObj = getOpenedDomainObject();
+			synchronized (fileSystem) {
 
-			if (keepCheckedOut) {
-				boolean exclusive = !versionedFileSystem.isShared();
-				ProjectLocator projectLocator = parent.getProjectLocator();
-				CheckoutType checkoutType;
-				if (projectLocator.isTransient()) {
-					checkoutType = CheckoutType.TRANSIENT;
-					exclusive = true;
+				String parentPath = parent.getPathname();
+				String user = ClientUtil.getUserName();
+				try {
+					if (folderItem instanceof DatabaseItem) {
+						DatabaseItem databaseItem = (DatabaseItem) folderItem;
+						BufferFile bufferFile = databaseItem.open();
+						try {
+							versionedFolderItem = versionedFileSystem.createDatabase(parentPath,
+								name, folderItem.getFileID(), bufferFile, comment,
+								folderItem.getContentType(), false, monitor, user);
+						}
+						finally {
+							bufferFile.dispose();
+						}
+					}
+					else if (folderItem instanceof DataFileItem) {
+						DataFileItem dataFileItem = (DataFileItem) folderItem;
+						InputStream istream = dataFileItem.getInputStream();
+						try {
+							versionedFolderItem = versionedFileSystem.createDataFile(parentPath,
+								name, istream, comment, folderItem.getContentType(), monitor);
+						}
+						finally {
+							istream.close();
+						}
+					}
+					else {
+						throw new AssertException("Unknown folder item type");
+					}
+				}
+				catch (InvalidNameException e) {
+					throw new AssertException("Unexpected error", e);
+				}
+
+				if (keepCheckedOut) {
+
+					// Maintain exclusive chekout if private repository or file is open for update
+					boolean exclusive = !versionedFileSystem.isShared() || (inUseDomainObj != null);
+
+					ProjectLocator projectLocator = parent.getProjectLocator();
+					CheckoutType checkoutType;
+					if (projectLocator.isTransient()) {
+						checkoutType = CheckoutType.TRANSIENT;
+						exclusive = true;
+					}
+					else {
+						// All checkouts for non-shared versioning are treated as exclusive
+						checkoutType =
+							(exclusive || !versionedFileSystem.isShared()) ? CheckoutType.EXCLUSIVE
+									: CheckoutType.NORMAL;
+					}
+					ItemCheckoutStatus checkout = versionedFolderItem.checkout(checkoutType, user,
+						ItemCheckoutStatus.getProjectPath(projectLocator.toString(),
+							projectLocator.isTransient()));
+					folderItem.setCheckout(checkout.getCheckoutId(), exclusive,
+						checkout.getCheckoutVersion(), folderItem.getCurrentVersion());
 				}
 				else {
-					// All checkouts for non-shared versioning are treated as exclusive
-					checkoutType =
-						(exclusive || !versionedFileSystem.isShared()) ? CheckoutType.EXCLUSIVE
-								: CheckoutType.NORMAL;
-				}
-				ItemCheckoutStatus checkout = versionedFolderItem.checkout(checkoutType, user,
-					ItemCheckoutStatus.getProjectPath(projectLocator.toString(),
-						projectLocator.isTransient()));
-				folderItem.setCheckout(checkout.getCheckoutId(), exclusive,
-					checkout.getCheckoutVersion(), folderItem.getCurrentVersion());
-			}
-			else {
-				if (oldDomainObj == null) {
+					// NOTE: file open read-only may prevent removal and result in hijack
 					try {
 						folderItem.delete(-1, ClientUtil.getUserName());
 						folderItem = null;
@@ -1111,27 +1127,23 @@ public class GhidraFileData {
 						// Ignore - should result in Hijacked file
 					}
 				}
-			}
-			if (oldDomainObj != null) {
 
-				// TODO: Develop way to re-use and re-init domain object instead of a switch-a-roo approach
+				if (inUseDomainObj != null) {
+					getContentHandler().resetDBSourceFile(folderItem, inUseDomainObj);
+				}
+			} // end of synchronized block
 
-				projectData.clearDomainObject(getPathname());
-
-				oldDomainObj.setDomainFile(new DomainFileProxy("~" + name, oldDomainObj));
-				oldDomainObj.setTemporary(true);
+			if (inUseDomainObj != null) {
+				inUseDomainObj.invalidate();
 			}
 		}
-		if (oldDomainObj != null) {
-			// Complete re-open of file
-			DomainFile df = getDomainFile();
-			listener.domainFileObjectClosed(df, oldDomainObj);
-			listener.domainFileObjectReplaced(df, oldDomainObj);
-		}
-		if (!keepCheckedOut) {
+		finally {
+			unlockDomainObject(inUseDomainObj);
+			busy.set(false);
+			projectData.mergeEnded();
 			parent.deleteLocalFolderIfEmpty();
+			parent.fileChanged(name);
 		}
-		statusChanged();
 	}
 
 	/**
@@ -1258,7 +1270,8 @@ public class GhidraFileData {
 				if (versionedFolderItem.getCurrentVersion() != folderItem.getCheckoutVersion()) {
 					return false;
 				}
-// TODO: assumes folderItem is local - should probably defer createNewVersion to folderItem if possible (requires refactor)
+				// TODO: assumes folderItem is local - should probably defer createNewVersion 
+				// to folderItem if possible (requires refactor)
 				srcFile = (LocalManagedBufferFile) ((DatabaseItem) folderItem).open();
 			}
 
@@ -1266,18 +1279,15 @@ public class GhidraFileData {
 			if (checkinHandler.createKeepFile()) {
 				DomainObject sourceObj = null;
 				try {
-					ContentHandler<?> ch = getContentHandler();
-					sourceObj = ch.getImmutableObject(folderItem, this, DomainFile.DEFAULT_VERSION,
-						-1, monitor);
+					sourceObj = getContentHandler().getImmutableObject(folderItem, this,
+						DomainFile.DEFAULT_VERSION, -1, monitor);
 					createKeepFile(sourceObj, monitor);
 				}
 				catch (VersionException e) {
 					// ignore - unable to create keep file
 				}
 				finally {
-					if (sourceObj != null) {
-						sourceObj.release(this);
-					}
+					release(sourceObj);
 				}
 			}
 			monitor.checkCancelled();
@@ -1298,13 +1308,13 @@ public class GhidraFileData {
 	}
 
 	/**
-	 * Verify that current user is the checkout user for this file
+	 * Verify checkout status and that current user is the checkout user for this file
 	 * @param operationName name of user case (e.g., checkin)
 	 * @throws IOException if server/repository will not permit current user to checkin,
 	 * or update checkout version of current file.  (i.e., server login does not match
 	 * user name used at time of initial checkout)
 	 */
-	private void verifyRepoUser(String operationName) throws IOException {
+	private void verifyCheckout(String operationName) throws IOException {
 		if (versionedFileSystem instanceof LocalFileSystem) {
 			return; // rely on local project ownership
 		}
@@ -1327,15 +1337,13 @@ public class GhidraFileData {
 	 * Performs check in to associated repository.  File must be checked-out 
 	 * and modified since checkout.
 	 * @param checkinHandler provides user input data to complete checkin process.
-	 * @param okToUpgrade if true an upgrade will be performed if needed
 	 * @param monitor the TaskMonitor.
 	 * @throws IOException if an IO or access error occurs
 	 * @throws VersionException if unable to handle domain object version in versioned filesystem.
-	 * If okToUpgrade was false, check exception to see if it can be upgraded
-	 * sometime after doing a checkout.
+	 * We are unable to upgrade since this would only occur if checkout is not exclusive.
 	 * @throws CancelledException if task monitor cancelled operation
 	 */
-	void checkin(CheckinHandler checkinHandler, boolean okToUpgrade, TaskMonitor monitor)
+	void checkin(CheckinHandler checkinHandler, TaskMonitor monitor)
 			throws IOException, VersionException, CancelledException {
 
 		if (!versionedFileSystem.isOnline()) {
@@ -1357,15 +1365,29 @@ public class GhidraFileData {
 		if (!modifiedSinceCheckout()) {
 			throw new IOException("File has not been modified since checkout");
 		}
-		verifyRepoUser("checkin");
+		verifyCheckout("checkin");
 		if (monitor == null) {
 			monitor = TaskMonitor.DUMMY;
 		}
+
 		if (busy.getAndSet(true)) {
 			throw new FileInUseException(name + " is busy");
 		}
+
+		DomainObjectAdapterDB inUseDomainObj = null;
 		projectData.mergeStarted();
 		try {
+			ContentHandler<?> contentHandler = getContentHandler();
+
+			inUseDomainObj = getAndLockInUseDomainObjectForMergeUpdate("checkin");
+
+			boolean keepCheckedOut = checkinHandler.keepCheckedOut();
+
+			if (inUseDomainObj != null && !keepCheckedOut) {
+				keepCheckedOut = true;
+				Msg.warn(this, "File currently open - must keep checked-out: " + name);
+			}
+
 			boolean quickCheckin = ALWAYS_MERGE ? false : quickCheckin(checkinHandler, monitor);
 
 			if (!quickCheckin) {
@@ -1377,9 +1399,8 @@ public class GhidraFileData {
 
 				Msg.info(this, "Checkin with merge for " + name);
 
-				ContentHandler<?> ch = getContentHandler();
-				DomainObjectAdapter checkinObj = ch.getDomainObject(versionedFolderItem, null,
-					folderItem.getCheckoutId(), okToUpgrade, false, this, monitor);
+				DomainObjectAdapter checkinObj = contentHandler.getDomainObject(versionedFolderItem,
+					null, folderItem.getCheckoutId(), false, false, this, monitor);
 				checkinObj.setDomainFile(new DomainFileProxy(name, getParent().getPathname(),
 					checkinObj, versionedFolderItem.getCurrentVersion() + 1, fileID,
 					parent.getProjectLocator()));
@@ -1390,15 +1411,15 @@ public class GhidraFileData {
 				try {
 					synchronized (fileSystem) {
 						int coVer = folderItem.getCheckoutVersion();
-						sourceObj = ch.getImmutableObject(folderItem, this,
+						sourceObj = contentHandler.getImmutableObject(folderItem, this,
 							DomainFile.DEFAULT_VERSION, -1, monitor);
-						originalObj =
-							ch.getImmutableObject(versionedFolderItem, this, coVer, -1, monitor);
-						latestObj = ch.getImmutableObject(versionedFolderItem, this,
+						originalObj = contentHandler.getImmutableObject(versionedFolderItem, this,
+							coVer, -1, monitor);
+						latestObj = contentHandler.getImmutableObject(versionedFolderItem, this,
 							DomainFile.DEFAULT_VERSION, coVer, monitor);
 					}
-					DomainObjectMergeManager mergeMgr =
-						ch.getMergeManager(checkinObj, sourceObj, originalObj, latestObj);
+					DomainObjectMergeManager mergeMgr = contentHandler.getMergeManager(checkinObj,
+						sourceObj, originalObj, latestObj);
 
 					if (!mergeMgr.merge(monitor)) {
 						Msg.info(this, "Checkin with merge terminated for " + name);
@@ -1417,27 +1438,14 @@ public class GhidraFileData {
 				}
 				finally {
 					checkinObj.release(this);
-					if (sourceObj != null) {
-						sourceObj.release(this);
-					}
-					if (originalObj != null) {
-						originalObj.release(this);
-					}
-					if (latestObj != null) {
-						latestObj.release(this);
-					}
+					release(sourceObj);
+					release(originalObj);
+					release(latestObj);
 				}
 			}
 
-			DomainObjectAdapter oldDomainObj = null;
-
-			FolderItem oldLocalItem = null;
-			boolean keepCheckedOut = checkinHandler.keepCheckedOut();
-
 			synchronized (fileSystem) {
 
-				oldDomainObj = getOpenedDomainObject();
-
 				versionedFolderItem = versionedFileSystem.getItem(parent.getPathname(), name);
 				if (versionedFolderItem == null) {
 					throw new IOException("Checkin failed, versioned item not found");
@@ -1456,7 +1464,17 @@ public class GhidraFileData {
 					}
 					finally {
 						if (!success) {
+							// Failed to update checkout for unknown reason
 							try {
+								if (inUseDomainObj != null) {
+									// On error disassociate open domain object from this file
+									projectData.clearDomainObject(getPathname());
+									// An invalid version (-2) is specified to avoid file match
+									inUseDomainObj.setDomainFile(new DomainFileProxy(name,
+										parent.getPathname(), inUseDomainObj, -2, fileID,
+										parent.getProjectLocator()));
+									inUseDomainObj.setTemporary(true);
+								}
 								undoCheckout(false, true);
 							}
 							catch (IOException e) {
@@ -1466,53 +1484,71 @@ public class GhidraFileData {
 					}
 				}
 				else {
-					if (oldDomainObj != null) {
-						oldLocalItem = folderItem;
-						folderItem = null;
-					}
-					else {
-						undoCheckout(false, true);
-					}
+					undoCheckout(false, true);
 				}
-				if (oldDomainObj != null) {
 
-					// TODO: Develop way to re-use and re-init domain object instead of a switch-a-roo approach
-
-					projectData.clearDomainObject(getPathname());
-
-					oldDomainObj.setDomainFile(new DomainFileProxy(name, parent.getPathname(),
-						oldDomainObj, -2, fileID, parent.getProjectLocator())); // invalid version (-2) specified to avoid file match
-					oldDomainObj.setTemporary(true);
+				if (inUseDomainObj != null) {
+					contentHandler.resetDBSourceFile(folderItem, inUseDomainObj);
 				}
-			}
 
-			if (oldDomainObj != null) {
-				// complete re-open of domain file
-				DomainFile df = getDomainFile();
-				listener.domainFileObjectClosed(df, oldDomainObj);
-				listener.domainFileObjectReplaced(df, oldDomainObj);
-			}
+			} // end of synchronized block
 
-			if (oldLocalItem != null) {
-				synchronized (fileSystem) {
-					// Undo checkout of old item - this will fail on Windows if item is open
-					long checkoutId = oldLocalItem.getCheckoutId();
-					oldLocalItem.delete(-1, ClientUtil.getUserName());
-					versionedFolderItem.terminateCheckout(checkoutId, true);
-				}
+			if (inUseDomainObj != null) {
+				inUseDomainObj.invalidate();
 			}
 		}
 		finally {
+			unlockDomainObject(inUseDomainObj);
 			busy.set(false);
-			try {
-				parent.deleteLocalFolderIfEmpty();
-				parent.fileChanged(name);
+			projectData.mergeEnded();
+			parent.deleteLocalFolderIfEmpty();
+			parent.fileChanged(name);
+		}
+	}
+
+	private void release(DomainObject domainObj) {
+		if (domainObj != null) {
+			domainObj.release(this);
+		}
+	}
+
+	private void unlockDomainObject(DomainObjectAdapterDB lockedDomainObject) {
+		try {
+			if (lockedDomainObject != null) {
+				lockedDomainObject.unlock();
 			}
-			finally {
-				projectData.mergeEnded();
+		}
+		catch (Exception e) {
+			Msg.error(this, "Unexpected " + getContentType() + " lock error: " + getName());
+		}
+	}
+
+	private DomainObjectAdapterDB getAndLockInUseDomainObjectForMergeUpdate(String operation)
+			throws IOException {
+		DomainObjectAdapterDB inUseDomainObj;
+		synchronized (fileSystem) {
+			DomainObjectAdapter domainObj = getOpenedDomainObject();
+			if (domainObj == null) {
+				return null;
+			}
+			// If we proceed with file in-use it must be instance of DomainObjectAdapterDB
+			if (!(domainObj instanceof DomainObjectAdapterDB)) {
+				throw new FileInUseException(name + " is in use");
+			}
+			inUseDomainObj = (DomainObjectAdapterDB) domainObj;
+			if (inUseDomainObj.isChanged()) {
+				throw new FileInUseException(name + " is in use w/ unsaved changes");
 			}
 		}
 
+		// Ensure that existing domain object will support DB merge update and is can be locked
+		ContentHandler<?> contentHandler = getContentHandler();
+		if (!contentHandler.canResetDBSourceFile() || !inUseDomainObj.lock(operation) ||
+			inUseDomainObj.getDBHandle().hasUncommittedChanges()) {
+			throw new FileInUseException(name + " is in use");
+		}
+
+		return inUseDomainObj;
 	}
 
 	/**
@@ -1619,7 +1655,7 @@ public class GhidraFileData {
 				throw new IOException("File not checked out");
 			}
 			if (!doForce) {
-				verifyRepoUser("undo-checkout");
+				verifyCheckout("undo-checkout");
 				long checkoutId = folderItem.getCheckoutId();
 				versionedFolderItem.terminateCheckout(checkoutId, true);
 			}
@@ -1666,7 +1702,7 @@ public class GhidraFileData {
 		return false;
 	}
 
-	private void createKeepFile(DomainObject oldDomainObj, TaskMonitor monitor) {
+	private void createKeepFile(DomainObject sourceObj, TaskMonitor monitor) {
 		String keepName = name + ".keep";
 		try {
 			GhidraFileData keepFileData = parent.getFileData(keepName, false);
@@ -1683,7 +1719,7 @@ public class GhidraFileData {
 			}
 			keepName = getKeepName();
 			Msg.info(this, "Creating old version keep file: " + keepName);
-			parent.createFile(keepName, oldDomainObj, monitor);
+			parent.createFile(keepName, sourceObj, monitor);
 		}
 		catch (InvalidNameException e) {
 			throw new AssertException("Unexpected error", e);
@@ -1765,10 +1801,10 @@ public class GhidraFileData {
 
 	private void removeAssociatedUserDataFile() {
 		try {
-			ContentHandler<?> ch = getContentHandler();
-			if (ch instanceof DBWithUserDataContentHandler) {
+			ContentHandler<?> contentHandler = getContentHandler();
+			if (contentHandler instanceof DBWithUserDataContentHandler) {
 				FolderItem item = folderItem != null ? folderItem : versionedFolderItem;
-				((DBWithUserDataContentHandler<?>) ch).removeUserDataFile(item,
+				((DBWithUserDataContentHandler<?>) contentHandler).removeUserDataFile(item,
 					parent.getUserFileSystem());
 			}
 		}
@@ -1812,7 +1848,7 @@ public class GhidraFileData {
 		if (canRecover()) {
 			throw new IOException("File recovery data exists");
 		}
-		verifyRepoUser("merge");
+		verifyCheckout("merge");
 		if (monitor == null) {
 			monitor = TaskMonitor.DUMMY;
 		}
@@ -1821,8 +1857,11 @@ public class GhidraFileData {
 		}
 
 		FolderItem tmpItem = null;
+		DomainObjectAdapterDB inUseDomainObj = null;
 		projectData.mergeStarted();
 		try {
+			inUseDomainObj = getAndLockInUseDomainObjectForMergeUpdate("merge");
+
 			if (!modifiedSinceCheckout()) {
 				// Quick merge
 				folderItem.updateCheckout(versionedFolderItem, true, monitor);
@@ -1830,17 +1869,17 @@ public class GhidraFileData {
 			else {
 
 				if (SystemUtilities.isInHeadlessMode()) {
-					throw new IOException(
-						"Merge failed, file merge is not supported in headless mode");
+					throw new IOException("Merge failed, merge is not supported in headless mode");
 				}
 
-				ContentHandler<?> ch = getContentHandler();
+				ContentHandler<?> contentHandler = getContentHandler();
 
 				// Test versioned file for VersionException
 				int mergeVer = versionedFolderItem.getCurrentVersion();
 				if (!okToUpgrade) {
-					DomainObject testObj =
-						ch.getReadOnlyObject(versionedFolderItem, mergeVer, false, this, monitor);
+					// verify remote version can be opened without verion error
+					DomainObject testObj = contentHandler.getReadOnlyObject(versionedFolderItem,
+						mergeVer, false, this, monitor);
 					testObj.release(this);
 				}
 
@@ -1866,21 +1905,21 @@ public class GhidraFileData {
 
 				tmpItem.setCheckout(checkoutId, folderItem.isCheckedOutExclusive(), mergeVer, 0);
 
-				DomainObject mergeObj =
-					ch.getDomainObject(tmpItem, null, -1, okToUpgrade, false, this, monitor);
+				DomainObject mergeObj = contentHandler.getDomainObject(tmpItem, null, -1,
+					okToUpgrade, false, this, monitor);
 				DomainObject sourceObj = null;
 				DomainObject originalObj = null;
 				DomainObject latestObj = null; // TODO: Is there some way to leverage the buffer file we already copied into tmpItem? Missing required change set
 				try {
-					sourceObj = ch.getImmutableObject(folderItem, this, DomainFile.DEFAULT_VERSION,
-						-1, monitor);
-					originalObj =
-						ch.getImmutableObject(versionedFolderItem, this, coVer, -1, monitor);
-					latestObj =
-						ch.getImmutableObject(versionedFolderItem, this, mergeVer, coVer, monitor);
+					sourceObj = contentHandler.getImmutableObject(folderItem, this,
+						DomainFile.DEFAULT_VERSION, -1, monitor);
+					originalObj = contentHandler.getImmutableObject(versionedFolderItem, this,
+						coVer, -1, monitor);
+					latestObj = contentHandler.getImmutableObject(versionedFolderItem, this,
+						mergeVer, coVer, monitor);
 
 					DomainObjectMergeManager mergeMgr =
-						ch.getMergeManager(mergeObj, sourceObj, originalObj, latestObj);
+						contentHandler.getMergeManager(mergeObj, sourceObj, originalObj, latestObj);
 
 					if (!mergeMgr.merge(monitor)) {
 						Msg.info(this, "Merge terminated for " + name);
@@ -1888,19 +1927,14 @@ public class GhidraFileData {
 					}
 
 					mergeObj.save("Merge with version " + mergeVer, monitor);
+
 					createKeepFile(sourceObj, monitor);
 				}
 				finally {
-					mergeObj.release(this);
-					if (sourceObj != null) {
-						sourceObj.release(this);
-					}
-					if (originalObj != null) {
-						originalObj.release(this);
-					}
-					if (latestObj != null) {
-						latestObj.release(this);
-					}
+					release(mergeObj);
+					release(sourceObj);
+					release(originalObj);
+					release(latestObj);
 				}
 
 				// Update folder item
@@ -1909,29 +1943,18 @@ public class GhidraFileData {
 					ClientUtil.getUserName());
 				tmpItem = null;
 				Msg.info(this, "Merge completed for " + name);
-			}
 
-			DomainObjectAdapter oldDomainObj = null;
-
-			// TODO: Develop way to re-use and re-init domain object instead of a switch-a-roo approach
-
-			synchronized (fileSystem) {
-				oldDomainObj = getOpenedDomainObject();
-				if (oldDomainObj != null) {
-					projectData.clearDomainObject(getPathname());
-					oldDomainObj.setDomainFile(new DomainFileProxy("~" + name, oldDomainObj));
-					oldDomainObj.setTemporary(true);
+				if (inUseDomainObj != null) {
+					contentHandler.resetDBSourceFile(folderItem, inUseDomainObj);
 				}
 			}
 
-			if (oldDomainObj != null) {
-				// Complete re-open of file
-				DomainFile df = getDomainFile();
-				listener.domainFileObjectClosed(df, oldDomainObj);
-				listener.domainFileObjectReplaced(df, oldDomainObj);
+			if (inUseDomainObj != null) {
+				inUseDomainObj.invalidate();
 			}
 		}
 		finally {
+			unlockDomainObject(inUseDomainObj);
 			busy.set(false);
 			try {
 				if (tmpItem != null) {
@@ -2281,19 +2304,22 @@ public class GhidraFileData {
 	/**
 	 * Returns an ordered map containing the metadata stored within a specific {@link FolderItem}
 	 * database. The map contains key,value pairs and are ordered by their insertion order. 
+	 * @param item folder item whose metadata should be read
 	 * @return a map containing the metadata that has been associated with the corresponding domain 
 	 * object.  Map will be empty for a non-database item.
 	 */
 	static Map<String, String> getMetadata(FolderItem item) {
+		if (!(item instanceof DatabaseItem databaseItem)) {
+			return new HashMap<>();
+		}
+		ManagedBufferFile bf = null;
+		DBHandle dbh = null;
 		GenericDomainObjectDB genericDomainObj = null;
 		try {
-			if (item instanceof DatabaseItem) {
-				DatabaseItem databaseItem = (DatabaseItem) item;
-				BufferFile bf = databaseItem.open();
-				DBHandle dbh = new DBHandle(bf);
-				genericDomainObj = new GenericDomainObjectDB(dbh);
-				return genericDomainObj.getMetadata();
-			}
+			bf = databaseItem.open();
+			dbh = new DBHandle(bf);
+			genericDomainObj = new GenericDomainObjectDB(dbh);
+			return genericDomainObj.getMetadata();
 		}
 		catch (FileNotFoundException e) {
 			// file has been deleted, just return an empty map.
@@ -2308,6 +2334,12 @@ public class GhidraFileData {
 			if (genericDomainObj != null) {
 				genericDomainObj.release();
 			}
+			if (dbh != null) {
+				dbh.close();
+			}
+			if (bf != null) {
+				bf.dispose();
+			}
 		}
 		return new HashMap<>();
 	}
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/LinkedGhidraFile.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/LinkedGhidraFile.java
index 21e155ae0d..a298700753 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/LinkedGhidraFile.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/data/LinkedGhidraFile.java
@@ -302,7 +302,7 @@ class LinkedGhidraFile implements LinkedDomainFile {
 	}
 
 	@Override
-	public void checkin(CheckinHandler checkinHandler, boolean okToUpgrade, TaskMonitor monitor)
+	public void checkin(CheckinHandler checkinHandler, TaskMonitor monitor)
 			throws IOException, VersionException, CancelledException {
 		throw new UnsupportedOperationException();
 	}
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatable/ProjectDataTablePanel.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatable/ProjectDataTablePanel.java
index f82a8e966f..ab7ddd41d9 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatable/ProjectDataTablePanel.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatable/ProjectDataTablePanel.java
@@ -96,8 +96,7 @@ public class ProjectDataTablePanel extends JPanel {
 			}
 		});
 		gTable.getSelectionModel()
-				.addListSelectionListener(
-					e -> plugin.getTool().contextChanged(null));
+				.addListSelectionListener(e -> plugin.getTool().contextChanged(null));
 		gTable.setDefaultRenderer(Date.class, new DateCellRenderer());
 		gTable.setDefaultRenderer(DomainFileType.class, new TypeCellRenderer());
 
@@ -364,11 +363,6 @@ public class ProjectDataTablePanel extends JPanel {
 			reload();
 		}
 
-		@Override
-		public void domainFolderSetActive(DomainFolder folder) {
-			// don't care
-		}
-
 		@Override
 		public void domainFileStatusChanged(DomainFile file, boolean fileIDset) {
 			if (ignoreChanges()) {
@@ -379,24 +373,6 @@ public class ProjectDataTablePanel extends JPanel {
 			plugin.getTool().contextChanged(null);
 		}
 
-		@Override
-		public void domainFileObjectReplaced(DomainFile file, DomainObject oldObject) {
-			if (ignoreChanges()) {
-				return;
-			}
-			clearInfo(file);
-			table.repaint();
-		}
-
-		@Override
-		public void domainFileObjectOpenedForUpdate(DomainFile file, DomainObject object) {
-			// don't care
-		}
-
-		@Override
-		public void domainFileObjectClosed(DomainFile file, DomainObject object) {
-			// don't care
-		}
 	}
 
 	/**
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/ChangeManager.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/ChangeManager.java
index 99da701708..8d62de971b 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/ChangeManager.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/ChangeManager.java
@@ -140,11 +140,6 @@ class ChangeManager implements DomainFolderChangeListener {
 		}
 	}
 
-//    @Override
-//    public void domainFileSaved(DomainFile file, DomainObject dobj) {
-//    	treePanel.getActionManager().adjustActions();	
-//    }
-
 	@Override
 	public void domainFileStatusChanged(DomainFile file, boolean fileIDset) {
 		DomainFileNode fileNode = findDomainFileNode(file, true);
@@ -152,7 +147,6 @@ class ChangeManager implements DomainFolderChangeListener {
 			fileNode.refresh();
 		}
 		treePanel.domainChange();
-//		treePanel.getActionManager().adjustActions();
 	}
 
 	private void getFolderPath(DomainFolder df, List<String> list) {
@@ -221,27 +215,4 @@ class ChangeManager implements DomainFolderChangeListener {
 		}
 	}
 
-	/* (non-Javadoc)
-	 * @see ghidra.framework.model.DomainFolderChangeListener#domainFileObjectReplaced(ghidra.framework.model.DomainFile, ghidra.framework.model.DomainObject)
-	 */
-	@Override
-	public void domainFileObjectReplaced(DomainFile file, DomainObject oldObject) {
-		// ignored
-	}
-
-	/*
-	 * @see ghidra.framework.model.DomainFolderChangeListener#domainFileObjectOpenedForUpdate(ghidra.framework.model.DomainFile, ghidra.framework.model.DomainObject)
-	 */
-	@Override
-	public void domainFileObjectOpenedForUpdate(DomainFile file, DomainObject object) {
-		// ignored
-	}
-
-	/*
-	 * @see ghidra.framework.model.DomainFolderChangeListener#domainFileObjectClosed(ghidra.framework.model.DomainFile, ghidra.framework.model.DomainObject)
-	 */
-	@Override
-	public void domainFileObjectClosed(DomainFile file, DomainObject object) {
-		// ignored
-	}
 }
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/CheckInTask.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/CheckInTask.java
index e68dfa1c0e..15a1fd4c98 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/CheckInTask.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/CheckInTask.java
@@ -54,11 +54,9 @@ public class CheckInTask extends VersionControlTask implements CheckinHandler {
 	private void promptUser() throws CancelledException {
 		if (newFile) {
 			newFile = false;
-			if (monitor.isCancelled()) {
-				throw new CancelledException();
-			}
+			monitor.checkCancelled();
 			if (actionID != VersionControlDialog.APPLY_TO_ALL) {
-				showDialog(false, df.getName(), df.isLinkFile()); // false==> checking in vs. 
+				showDialog(false, df);
 				// adding to version control
 				if (actionID == VersionControlDialog.CANCEL) {
 					monitor.cancel();
@@ -69,23 +67,16 @@ public class CheckInTask extends VersionControlTask implements CheckinHandler {
 		}
 	}
 
-	/* (non-Javadoc)
-	 * @see ghidra.util.task.Task#run(ghidra.util.task.TaskMonitor)
-	 */
 	@Override
 	public void run(TaskMonitor myMonitor) {
 		this.monitor = myMonitor;
 		myMonitor.setMessage("Examining selected file(s)");
-//		checkFilesInUse();
-
 		String currentName = null;
-		String currentContentType = null;
 		try {
 			for (int i = 0; i < list.size() && actionID != VersionControlDialog.CANCEL; i++) {
 
 				df = list.get(i);
 				currentName = df.getName();
-				currentContentType = df.getContentType();
 				newFile = true;
 
 				if (i != 0) {
@@ -94,27 +85,23 @@ public class CheckInTask extends VersionControlTask implements CheckinHandler {
 						Thread.sleep(200);
 					}
 					catch (InterruptedException e2) {
+						break;
 					}
 				}
 
 				myMonitor.setMessage("Initiating Check In for " + currentName);
 				try {
-					df.checkin(this, false, myMonitor);
+					df.checkin(this, myMonitor);
 				}
 				catch (VersionException e) {
-					if (VersionExceptionHandler.isUpgradeOK(parent, df, "Checkin", e)) {
-						df.checkin(this, true, myMonitor);
-					}
+					VersionExceptionHandler.showVersionError(parent, df.getName(),
+						df.getContentType(), "Checkin", e);
 				}
 				if (myMonitor.isCancelled()) {
 					break;
 				}
 			}
 		}
-		catch (VersionException e) {
-			VersionExceptionHandler.showVersionError(parent, df.getName(), currentContentType,
-				"Checkin", e);
-		}
 		catch (CancelledException e) {
 			Msg.info(this, "Check In Process was canceled");
 			wasCanceled = true;
@@ -125,18 +112,12 @@ public class CheckInTask extends VersionControlTask implements CheckinHandler {
 		}
 	}
 
-	/*
-	 * @see ghidra.framework.data.CheckinHandler#getComment()
-	 */
 	@Override
 	public String getComment() throws CancelledException {
 		promptUser();
 		return comments;
 	}
 
-	/*
-	 * @see ghidra.framework.data.CheckinHandler#keepCheckedOut()
-	 */
 	@Override
 	public boolean keepCheckedOut() throws CancelledException {
 		promptUser();
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/VersionControlTask.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/VersionControlTask.java
index 9e21bbd4f3..964519907b 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/VersionControlTask.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/VersionControlTask.java
@@ -57,21 +57,22 @@ public abstract class VersionControlTask extends Task {
 	 * Show the dialog.
 	 * @param addToVersionControl true if the dialog is for
 	 * adding files to version control, false for checking in files.
-	 * @param filename the name of the file currently to be added, whose comment we need.
-	 * @param isLinkFile true if file is a link file, else false.  Link-files may not be checked-out
-	 * so keep-checked-out control disabled if this is true.
+	 * @param file the file currently to be added or checked-in to version control
 	 */
-	protected void showDialog(boolean addToVersionControl, String filename, boolean isLinkFile) {
+	protected void showDialog(boolean addToVersionControl, DomainFile file) {
 		Runnable r = () -> {
 			VersionControlDialog vcDialog = new VersionControlDialog(addToVersionControl);
-			vcDialog.setCurrentFileName(filename);
+			vcDialog.setCurrentFileName(file.getName());
 			vcDialog.setMultiFiles(list.size() > 1);
-			if (isLinkFile) {
-				vcDialog.setKeepCheckboxEnabled(false, false, "Link files may not be Checked Out");
+			if (file.isLinkFile()) {
+				vcDialog.setKeepCheckboxEnabled(false, false, "Link file may not be Checked Out");
 			}
-			else if (filesInUse) {
-				vcDialog.setKeepCheckboxEnabled(false, true,
-					"Must keep Checked Out because the file is in use");
+			else {
+				checkFilesInUse();
+				if (filesInUse) {
+					vcDialog.setKeepCheckboxEnabled(false, true,
+						"Must keep Checked Out because the file is in use");
+				}
 			}
 			actionID = vcDialog.showDialog(tool, parent);
 			keepCheckedOut = vcDialog.keepCheckedOut();
@@ -93,9 +94,11 @@ public abstract class VersionControlTask extends Task {
 	 * are still in use.
 	 */
 	protected void checkFilesInUse() {
+		// NOTE: In-use check is currently limited to files open for update but for the purpose of 
+		// maintaining a checkout should really correspond to any file use (e.g., open read-only
+		// with DomainFileProxy).
 		filesInUse = false;
-		for (int i = 0; i < list.size(); i++) {
-			DomainFile df = list.get(i);
+		for (DomainFile df : list) {
 			if (df.getConsumers().size() > 0) {
 				filesInUse = true;
 				return;
@@ -104,8 +107,7 @@ public abstract class VersionControlTask extends Task {
 	}
 
 	protected boolean checkFilesForUnsavedChanges() {
-		for (int i = 0; i < list.size(); i++) {
-			DomainFile df = list.get(i);
+		for (DomainFile df : list) {
 			if (df.modifiedSinceCheckout()) {
 				return true;
 			}
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/projectdata/actions/VersionControlAddAction.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/projectdata/actions/VersionControlAddAction.java
index d89d1637c6..823b122266 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/projectdata/actions/VersionControlAddAction.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/main/projectdata/actions/VersionControlAddAction.java
@@ -136,14 +136,13 @@ public class VersionControlAddAction extends VersionControlAction {
 
 		@Override
 		public void run(TaskMonitor monitor) {
-			checkFilesInUse();
 			try {
 				for (DomainFile df : list) {
 					String name = df.getName();
 					monitor.setMessage("Adding " + name + " to Version Control");
 
 					if (actionID != VersionControlDialog.APPLY_TO_ALL) {
-						showDialog(true, name, df.isLinkFile());
+						showDialog(true, df);
 					}
 					if (actionID == VersionControlDialog.CANCEL) {
 						return;
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/model/DomainFile.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/model/DomainFile.java
index d2c5fa2016..b9fdae05f8 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/model/DomainFile.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/model/DomainFile.java
@@ -305,19 +305,34 @@ public interface DomainFile extends Comparable<DomainFile> {
 
 	/**
 	 * Returns true if this file may be checked-in to the associated repository.
-	 * @return true if can check-in
+	 * 
+	 * Note: this does not take into consideration cases where the file is currently
+	 * in-use which may cause a failure if a checkin is attempted.
+	 * 
+	 * @return true if a check-in can be attempted (i.e., file is checked-out with changes),
+	 * else false
 	 */
 	public boolean canCheckin();
 
 	/**
 	 * Returns true if this file can be merged with the current versioned file.
-	 * @return true if can merge
+	 * 
+	 * Note: this does not take into consideration cases where the file is currently
+	 * in-use which may cause a failure if a merge is attempted.
+	 * 
+	 * @return true if a merge can be attempted (i.e., file is checked-out and a newer 
+	 * version exists), else false
 	 */
 	public boolean canMerge();
 
 	/**
 	 * Returns true if this private file may be added to the associated repository.
-	 * @return true if can add to the repository
+	 * 
+	 * Note: this does not take into consideration cases where the file is currently
+	 * in-use which may cause a failure if add to repository is attempted.
+	 * 
+	 * @return true if add to the repository can be attempted (i.e., file in active project
+	 * is not versioned or hijacked)
 	 */
 	public boolean canAddToRepository();
 
@@ -381,7 +396,8 @@ public interface DomainFile extends Comparable<DomainFile> {
 	/** 
 	 * Adds this private file to version control.
 	 * @param comment new version comment
-	 * @param keepCheckedOut if true, the file will be initially checked-out
+	 * @param keepCheckedOut if true, the file will be initially checked-out.  This option will be
+	 * ignored if file is currently open in which case file will remain checked-out.
 	 * @param monitor progress monitor
 	 * @throws FileInUseException if this file is in-use.
 	 * @throws IOException if an IO or access error occurs.  Also if file is not 
@@ -405,20 +421,42 @@ public interface DomainFile extends Comparable<DomainFile> {
 	public boolean checkout(boolean exclusive, TaskMonitor monitor)
 			throws IOException, CancelledException;
 
+	/**
+	* Performs check in to associated repository.  File must be checked-out 
+	* and modified since checkout.
+	* @param checkinHandler provides user input data to complete checkin process.
+	* The keep-checked-out option supplied by this handler will be ignored if file is currently 
+	* open in which case file will remain checked-out.
+	* @param monitor the TaskMonitor.
+	* @throws IOException if an IO or access error occurs
+	* @throws VersionException if unable to handle domain object version in versioned filesystem.
+	* We are unable to upgrade since this would only occur if checkout is not exclusive.
+	* @throws CancelledException if task monitor cancelled operation
+	*/
+	public void checkin(CheckinHandler checkinHandler, TaskMonitor monitor)
+			throws IOException, VersionException, CancelledException;
+
 	/**
 	 * Performs check in to associated repository.  File must be checked-out 
 	 * and modified since checkout.
 	 * @param checkinHandler provides user input data to complete checkin process.
-	 * @param okToUpgrade if true an upgrade will be performed if needed
+	 * This keep-checked-out option supplied by this handler will be ignored and forced true 
+	 * if file is currently open.
+	 * @param okToUpgrade if true an upgrade will be performed if needed (ignored)
 	 * @param monitor the TaskMonitor.
 	 * @throws IOException if an IO or access error occurs
 	 * @throws VersionException if unable to handle domain object version in versioned filesystem.
 	 * If okToUpgrade was false, check exception to see if it can be upgraded
 	 * sometime after doing a checkout.
 	 * @throws CancelledException if task monitor cancelled operation
+	 * @deprecated use alternative {@link #checkin(CheckinHandler, TaskMonitor)} method since
+	 * okToUpgrade cannot be respected and is ignored.  Upgrade cannot be performed during checkin.
 	 */
-	public void checkin(CheckinHandler checkinHandler, boolean okToUpgrade, TaskMonitor monitor)
-			throws IOException, VersionException, CancelledException;
+	@Deprecated(since = "11.1", forRemoval = true)
+	public default void checkin(CheckinHandler checkinHandler, boolean okToUpgrade,
+			TaskMonitor monitor) throws IOException, VersionException, CancelledException {
+		checkin(checkinHandler, monitor);
+	}
 
 	/**
 	 * Performs merge from current version of versioned file into local checked-out file. 
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/model/DomainFolderChangeListener.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/model/DomainFolderChangeListener.java
index 43567d3024..92afd300bc 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/model/DomainFolderChangeListener.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/model/DomainFolderChangeListener.java
@@ -1,6 +1,5 @@
 /* ###
  * IP: GHIDRA
- * REVIEWED: YES
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,21 +25,27 @@ public interface DomainFolderChangeListener {
 	 * Notification that a folder is added to parent.
 	 * @param folder domain folder which was just added.
 	 */
-	public void domainFolderAdded(DomainFolder folder);
+	public default void domainFolderAdded(DomainFolder folder) {
+		// do nothing
+	}
 
 	/**
 	 * Notification that a file is added to parent folder. You can
 	 * get the parent from the file.
 	 * @param file domain file which was just added.
 	 */
-	public void domainFileAdded(DomainFile file);
+	public default void domainFileAdded(DomainFile file) {
+		// do nothing
+	}
 
 	/**
 	 * Notification that a domain folder is removed.
 	 * @param parent domain folder which contained the folder that was just removed.
 	 * @param name the name of the folder that was removed.
 	 */
-	public void domainFolderRemoved(DomainFolder parent, String name);
+	public default void domainFolderRemoved(DomainFolder parent, String name) {
+		// do nothing
+	}
 
 	/**
 	 * Notification that a file was removed
@@ -48,40 +53,54 @@ public interface DomainFolderChangeListener {
 	 * @param name the name of the file that was removed.
 	 * @param fileID file ID or null
 	 */
-	public void domainFileRemoved(DomainFolder parent, String name, String fileID);
+	public default void domainFileRemoved(DomainFolder parent, String name, String fileID) {
+		// do nothing
+	}
 
 	/**
 	 * Notify listeners when a domain folder is renamed.
 	 * @param folder folder that was renamed
 	 * @param oldName old name of folder
 	 */
-	public void domainFolderRenamed(DomainFolder folder, String oldName);
+	public default void domainFolderRenamed(DomainFolder folder, String oldName) {
+		// do nothing
+	}
 
 	/**
 	 * Notification that the domain file was renamed.
 	 * @param file file that was renamed
 	 * @param oldName old name of the file
 	 */
-	public void domainFileRenamed(DomainFile file, String oldName);
+	public default void domainFileRenamed(DomainFile file, String oldName) {
+		// do nothing
+	}
 
 	/**
 	 * Notification that the domain folder was moved.
 	 * @param folder the folder (after move)
 	 * @param oldParent original parent folder
 	 */
-	public void domainFolderMoved(DomainFolder folder, DomainFolder oldParent);
+	public default void domainFolderMoved(DomainFolder folder, DomainFolder oldParent) {
+		// do nothing
+	}
 
 	/**
 	 * Notification that the domain file was moved.
 	 * @param file the file (after move)
 	 * @param oldParent original parent folder
+	 * @param oldName file name prior to move
 	 */
-	public void domainFileMoved(DomainFile file, DomainFolder oldParent, String oldName);
+	public default void domainFileMoved(DomainFile file, DomainFolder oldParent, String oldName) {
+		// do nothing
+	}
 
 	/**
 	 * Notification that the setActive() method on the folder was called.
+	 * @param folder folder which was activated/visited
 	 */
-	public void domainFolderSetActive(DomainFolder folder);
+	public default void domainFolderSetActive(DomainFolder folder) {
+		// do nothing
+	}
 
 	/**
 	 * Notification that the status for a domain file has changed.
@@ -89,30 +108,25 @@ public interface DomainFolderChangeListener {
 	 * @param fileIDset if true indicates that the previously missing fileID has been
 	 * established for the specified file.
 	 */
-	public void domainFileStatusChanged(DomainFile file, boolean fileIDset);
-
-	/**
-	 * Notification that a new version of the domain object exists and the
-	 * current one is no longer valid. Existing consumers should be immediately
-	 * released and no additional use of the oldObject is permitted once this 
-	 * method returns.  This is only called for domain objects which were
-	 * opened for update.
-	 * @param file file whose object was replaced
-	 * @param oldObject old object that was replaced
-	 */
-	public void domainFileObjectReplaced(DomainFile file, DomainObject oldObject);
+	public default void domainFileStatusChanged(DomainFile file, boolean fileIDset) {
+		// do nothing
+	}
 
 	/**
 	 * Notification that a domain file has been opened for update.
 	 * @param file domain file
 	 * @param object domain object open for update
 	 */
-	public void domainFileObjectOpenedForUpdate(DomainFile file, DomainObject object);
+	public default void domainFileObjectOpenedForUpdate(DomainFile file, DomainObject object) {
+		// do nothing
+	}
 
 	/**
 	 * Notification that a domain file previously open for update is in the process of closing.
 	 * @param file domain file
 	 * @param object domain object which was open for update
 	 */
-	public void domainFileObjectClosed(DomainFile file, DomainObject object);
+	public default void domainFileObjectClosed(DomainFile file, DomainObject object) {
+		// do nothing
+	}
 }
diff --git a/Ghidra/Framework/Project/src/main/java/ghidra/framework/model/DomainFolderListenerAdapter.java b/Ghidra/Framework/Project/src/main/java/ghidra/framework/model/DomainFolderListenerAdapter.java
index 21506d4fd5..c56484e9c4 100644
--- a/Ghidra/Framework/Project/src/main/java/ghidra/framework/model/DomainFolderListenerAdapter.java
+++ b/Ghidra/Framework/Project/src/main/java/ghidra/framework/model/DomainFolderListenerAdapter.java
@@ -122,11 +122,6 @@ public abstract class DomainFolderListenerAdapter implements DomainFolderChangeL
 			stateChanged(file.getPathname(), getPathname(oldParent, oldName), false);
 	}
 
-	@Override
-	public void domainFolderSetActive(DomainFolder folder) {
-		// do nothing
-	}
-
 	@Override
 	public void domainFileStatusChanged(DomainFile file, boolean fileIDset) {
 		if (enableStateChangeCallback) {
@@ -135,18 +130,4 @@ public abstract class DomainFolderListenerAdapter implements DomainFolderChangeL
 		}
 	}
 
-	@Override
-	public void domainFileObjectReplaced(DomainFile file, DomainObject oldObject) {
-		// do nothing
-	}
-
-	@Override
-	public void domainFileObjectOpenedForUpdate(DomainFile file, DomainObject object) {
-		// do nothing
-	}
-
-	@Override
-	public void domainFileObjectClosed(DomainFile file, DomainObject object) {
-		// do nothing
-	}
 }
diff --git a/Ghidra/Framework/Project/src/test/java/ghidra/framework/model/TestDummyDomainFile.java b/Ghidra/Framework/Project/src/test/java/ghidra/framework/model/TestDummyDomainFile.java
index 1be5916211..bf9239f46c 100644
--- a/Ghidra/Framework/Project/src/test/java/ghidra/framework/model/TestDummyDomainFile.java
+++ b/Ghidra/Framework/Project/src/test/java/ghidra/framework/model/TestDummyDomainFile.java
@@ -287,7 +287,7 @@ public class TestDummyDomainFile implements DomainFile {
 	}
 
 	@Override
-	public void checkin(CheckinHandler checkinHandler, boolean okToUpgrade, TaskMonitor monitor)
+	public void checkin(CheckinHandler checkinHandler, TaskMonitor monitor)
 			throws IOException, VersionException, CancelledException {
 		throw new UnsupportedOperationException();
 	}
diff --git a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/DataTypeArchiveContentHandler.java b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/DataTypeArchiveContentHandler.java
index 907f8f83f7..0ffb16c67a 100644
--- a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/DataTypeArchiveContentHandler.java
+++ b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/DataTypeArchiveContentHandler.java
@@ -21,14 +21,13 @@ import javax.swing.Icon;
 
 import db.DBConstants;
 import db.DBHandle;
-import db.buffers.BufferFile;
-import db.buffers.ManagedBufferFile;
+import db.buffers.*;
 import generic.theme.GIcon;
-import ghidra.framework.data.DBContentHandler;
-import ghidra.framework.data.DomainObjectMergeManager;
+import ghidra.framework.data.*;
 import ghidra.framework.model.ChangeSet;
 import ghidra.framework.model.DomainObject;
 import ghidra.framework.store.*;
+import ghidra.framework.store.local.LocalDatabaseItem;
 import ghidra.util.InvalidNameException;
 import ghidra.util.Msg;
 import ghidra.util.exception.CancelledException;
@@ -371,4 +370,21 @@ public class DataTypeArchiveContentHandler extends DBContentHandler<DataTypeArch
 		return linkHandler;
 	}
 
+	@Override
+	public boolean canResetDBSourceFile() {
+		return true;
+	}
+
+	@Override
+	public void resetDBSourceFile(FolderItem item, DomainObjectAdapterDB domainObj)
+			throws IOException {
+		if (!(item instanceof LocalDatabaseItem dbItem) ||
+			!(domainObj instanceof DataTypeArchiveDB dataTypeArchive)) {
+			throw new IllegalArgumentException("LocalDatabaseItem and DataTypeArchiveDB required");
+		}
+		LocalManagedBufferFile bf = dbItem.openForUpdate(FolderItem.DEFAULT_CHECKOUT_ID);
+		dataTypeArchive.getDBHandle().setDBVersionedSourceFile(bf);
+		getDataTypeArchiveChangeSet(dataTypeArchive, bf);
+	}
+
 }
diff --git a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/DataTypeArchiveDB.java b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/DataTypeArchiveDB.java
index a56d640ac2..91b8a5cbea 100644
--- a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/DataTypeArchiveDB.java
+++ b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/DataTypeArchiveDB.java
@@ -509,9 +509,6 @@ public class DataTypeArchiveDB extends DomainObjectAdapterDB implements DataType
 		}
 	}
 
-	/**
-	 * @see ghidra.program.model.listing.Program#invalidate()
-	 */
 	@Override
 	public void invalidate() {
 		clearCache(false);
diff --git a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/ProgramContentHandler.java b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/ProgramContentHandler.java
index 402b6e0cc9..c979757dcc 100644
--- a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/ProgramContentHandler.java
+++ b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/ProgramContentHandler.java
@@ -20,14 +20,13 @@ import java.io.IOException;
 import javax.swing.Icon;
 
 import db.*;
-import db.buffers.BufferFile;
-import db.buffers.ManagedBufferFile;
+import db.buffers.*;
 import generic.theme.GIcon;
-import ghidra.framework.data.DBWithUserDataContentHandler;
-import ghidra.framework.data.DomainObjectMergeManager;
+import ghidra.framework.data.*;
 import ghidra.framework.model.ChangeSet;
 import ghidra.framework.model.DomainObject;
 import ghidra.framework.store.*;
+import ghidra.framework.store.local.LocalDatabaseItem;
 import ghidra.util.InvalidNameException;
 import ghidra.util.Msg;
 import ghidra.util.exception.CancelledException;
@@ -58,8 +57,7 @@ public class ProgramContentHandler extends DBWithUserDataContentHandler<ProgramD
 		if (!(obj instanceof ProgramDB)) {
 			throw new IOException("Unsupported domain object: " + obj.getClass().getName());
 		}
-		return createFile((ProgramDB) obj, PROGRAM_CONTENT_TYPE, fs, path, name,
-			monitor);
+		return createFile((ProgramDB) obj, PROGRAM_CONTENT_TYPE, fs, path, name, monitor);
 	}
 
 	@Override
@@ -363,4 +361,21 @@ public class ProgramContentHandler extends DBWithUserDataContentHandler<ProgramD
 		return linkHandler;
 	}
 
+	@Override
+	public boolean canResetDBSourceFile() {
+		return true;
+	}
+
+	@Override
+	public void resetDBSourceFile(FolderItem item, DomainObjectAdapterDB domainObj)
+			throws IOException {
+		if (!(item instanceof LocalDatabaseItem dbItem) ||
+			!(domainObj instanceof ProgramDB program)) {
+			throw new IllegalArgumentException("LocalDatabaseItem and ProgramDB required");
+		}
+		LocalManagedBufferFile bf = dbItem.openForUpdate(FolderItem.DEFAULT_CHECKOUT_ID);
+		program.getDBHandle().setDBVersionedSourceFile(bf);
+		getProgramChangeSet(program, bf);
+	}
+
 }
diff --git a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/ProgramDB.java b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/ProgramDB.java
index 6a6926db7e..ebd87becbe 100644
--- a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/ProgramDB.java
+++ b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/ProgramDB.java
@@ -1842,12 +1842,6 @@ public class ProgramDB extends DomainObjectAdapterDB implements Program, ChangeM
 		}
 	}
 
-	@Override
-	public void invalidate() {
-		clearCache(false);
-		fireEvent(new DomainObjectChangeRecord(DomainObjectEvent.RESTORED));
-	}
-
 	@Override
 	public boolean isChangeable() {
 		return changeable;
diff --git a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/listing/Program.java b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/listing/Program.java
index 2fd7d0032a..046fb22be3 100644
--- a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/listing/Program.java
+++ b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/listing/Program.java
@@ -356,12 +356,6 @@ public interface Program extends DataTypeManagerDomainObject, ProgramArchitectur
 	 */
 	public Address[] parseAddress(String addrStr, boolean caseSensitive);
 
-	/**
-	 * Invalidates any caching in a program.
-	 * NOTE: Over-using this method can adversely affect system performance.
-	 */
-	public void invalidate();
-
 	/**
 	 * Create a new overlay space based upon the given base AddressSpace
 	 * @param overlaySpaceName the name of the new overlay space.
diff --git a/Ghidra/Framework/SoftwareModeling/src/test/java/ghidra/program/model/StubProgram.java b/Ghidra/Framework/SoftwareModeling/src/test/java/ghidra/program/model/StubProgram.java
index 1a1b854b04..0930afb095 100644
--- a/Ghidra/Framework/SoftwareModeling/src/test/java/ghidra/program/model/StubProgram.java
+++ b/Ghidra/Framework/SoftwareModeling/src/test/java/ghidra/program/model/StubProgram.java
@@ -536,11 +536,6 @@ public class StubProgram implements Program {
 		throw new UnsupportedOperationException();
 	}
 
-	@Override
-	public void invalidate() {
-		throw new UnsupportedOperationException();
-	}
-
 	@Override
 	public Register getRegister(String name) {
 		throw new UnsupportedOperationException();
diff --git a/Ghidra/Test/IntegrationTest/src/screen/java/help/screenshot/ProgramManagerPluginScreenShots.java b/Ghidra/Test/IntegrationTest/src/screen/java/help/screenshot/ProgramManagerPluginScreenShots.java
index 0593c26f14..b3b2bf109b 100644
--- a/Ghidra/Test/IntegrationTest/src/screen/java/help/screenshot/ProgramManagerPluginScreenShots.java
+++ b/Ghidra/Test/IntegrationTest/src/screen/java/help/screenshot/ProgramManagerPluginScreenShots.java
@@ -126,13 +126,13 @@ public class ProgramManagerPluginScreenShots extends GhidraScreenShotGenerator
 		checkinComment = "Version 2";
 		keepCheckedOut = true;
 		assertTrue(df.canCheckin());
-		df.checkin(this, false, null);
+		df.checkin(this, null);
 
 		changeProgram(p, "bbb");
 		checkinComment = "Version 3";
 		keepCheckedOut = true;
 		assertTrue(df.canCheckin());
-		df.checkin(this, false, null);
+		df.checkin(this, null);
 
 		p.release(this);
 		performAction("Open File", "ProgramManagerPlugin", false);
diff --git a/Ghidra/Test/IntegrationTest/src/test.slow/java/ghidra/framework/main/datatree/VersionControlAction1Test.java b/Ghidra/Test/IntegrationTest/src/test.slow/java/ghidra/framework/main/datatree/VersionControlAction1Test.java
index 8ab9ead6d4..b2bc190848 100644
--- a/Ghidra/Test/IntegrationTest/src/test.slow/java/ghidra/framework/main/datatree/VersionControlAction1Test.java
+++ b/Ghidra/Test/IntegrationTest/src/test.slow/java/ghidra/framework/main/datatree/VersionControlAction1Test.java
@@ -216,21 +216,21 @@ public class VersionControlAction1Test extends AbstractVersionControlActionTest
 
 		// make some changes to check in
 		Program program = (Program) ((DomainFileNode) node).getDomainFile()
-				.getDomainObject(this,
-					true, false, TaskMonitor.DUMMY);
+				.getDomainObject(this, true, false, TaskMonitor.DUMMY);
 		editProgram(program, (p) -> {
 			SymbolTable symTable = p.getSymbolTable();
 			symTable.createLabel(p.getMinAddress().getNewAddress(0x010001000), "fred",
 				SourceType.USER_DEFINED);
 		});
+		program.release(this);
 
 		program = (Program) ((DomainFileNode) xnode).getDomainFile()
-				.getDomainObject(this, true,
-					false, TaskMonitor.DUMMY);
+				.getDomainObject(this, true, false, TaskMonitor.DUMMY);
 		editProgram(program, (p) -> {
 			SymbolTable symTable = p.getSymbolTable();
 			symTable.createLabel(p.getMinAddress(), "bob", SourceType.USER_DEFINED);
 		});
+		program.release(this);
 
 		DockingActionIf checkInAction = getAction("CheckIn");
 		performAction(checkInAction, getDomainFileActionContext(node, xnode), false);
@@ -254,10 +254,8 @@ public class VersionControlAction1Test extends AbstractVersionControlActionTest
 
 		checkout(programNode);
 
-		Program program =
-			(Program) ((DomainFileNode) programNode).getDomainFile()
-					.getDomainObject(this, true,
-						false, TaskMonitor.DUMMY);
+		Program program = (Program) ((DomainFileNode) programNode).getDomainFile()
+				.getDomainObject(this, true, false, TaskMonitor.DUMMY);
 
 		createHistoryEntry(program, "Symbol1");
 		frontEnd.checkIn(programNode, "This is checkin 1");