Bug 449781. Toggling display on a subframe shouldn't give the subframe's document the same device context as the parent document. r=roc, sr=jst

docshell/base/nsDocShell.cpp

@@ -192,7 +192,6 @@
 
 #include "nsPluginError.h"
 
-static NS_DEFINE_IID(kDeviceContextCID, NS_DEVICE_CONTEXT_CID);
 static NS_DEFINE_CID(kDOMScriptObjectFactoryCID,
                      NS_DOM_SCRIPT_OBJECT_FACTORY_CID);
 static NS_DEFINE_CID(kAppShellCID, NS_APPSHELL_CID);
@@ -6389,16 +6388,9 @@ nsDocShell::SetupNewViewer(nsIContentViewer * aNewViewer)
     nsCOMPtr<nsIWidget> widget;
     NS_ENSURE_SUCCESS(GetMainWidget(getter_AddRefs(widget)), NS_ERROR_FAILURE);
 
-    nsCOMPtr<nsIDeviceContext> deviceContext;
-    if (widget) {
-        deviceContext = do_CreateInstance(kDeviceContextCID);
-        NS_ENSURE_TRUE(deviceContext, NS_ERROR_FAILURE);
-        deviceContext->Init(widget->GetNativeData(NS_NATIVE_WIDGET));
-    }
-
     nsRect bounds(x, y, cx, cy);
 
-    if (NS_FAILED(mContentViewer->Init(widget, deviceContext, bounds))) {
+    if (NS_FAILED(mContentViewer->Init(widget, bounds))) {
         mContentViewer = nsnull;
         NS_ERROR("ContentViewer Initialization failed");
         return NS_ERROR_FAILURE;

docshell/base/nsIContentViewer.idl

@@ -7,20 +7,17 @@ interface nsIPrintSettings;
 
 %{ C++
 class nsIWidget;
-class nsIDeviceContext;
 struct nsRect;
 %}
 
 [ptr] native nsIWidgetPtr(nsIWidget);
-[ptr] native nsIDeviceContextPtr(nsIDeviceContext);
 [ref] native nsRectRef(nsRect);
 
-[scriptable, uuid(89653afe-182f-401f-9f3c-8858d91387cd)]
+[scriptable, uuid(05b290ac-d880-4900-bb1f-2211b5f8accc)]
 interface nsIContentViewer : nsISupports
 {
 
   [noscript] void init(in nsIWidgetPtr aParentWidget,
-                       in nsIDeviceContextPtr aDeviceContext,
                        [const] in nsRectRef aBounds);
 
   attribute nsISupports container;

layout/base/nsDocumentViewer.cpp

@@ -357,9 +357,17 @@ private:
    * @param aSize the initial size in appunits
    */
   nsresult MakeWindow(const nsSize& aSize);
+
+  /**
+   * Create our device context
+   */
+  nsresult CreateDeviceContext(nsIWidget* aWidget);
+
+  /**
+   * Make sure to set up mDeviceContext as needed before calling this
+   */
   nsresult InitInternal(nsIWidget* aParentWidget,
                         nsISupports *aState,
-                        nsIDeviceContext* aDeviceContext,
                         const nsRect& aBounds,
                         PRBool aDoCreation,
                         PRBool aInPrintPreview,
@@ -407,7 +415,7 @@ protected:
   // class, please make the ownership explicit (pinkerton, scc).
 
   nsWeakPtr mContainer; // it owns me!
-  nsCOMPtr<nsIDeviceContext> mDeviceContext;   // ??? can't hurt, but...
+  nsCOMPtr<nsIDeviceContext> mDeviceContext;  // We create and own this baby
 
   // the following six items are explicitly in this order
   // so they will be destroyed in the reverse order (pinkerton, scc)
@@ -480,6 +488,7 @@ protected:
 // Class IDs
 static NS_DEFINE_CID(kViewManagerCID,       NS_VIEW_MANAGER_CID);
 static NS_DEFINE_CID(kWidgetCID,            NS_CHILD_CID);
+static NS_DEFINE_CID(kDeviceContextCID,     NS_DEVICE_CONTEXT_CID);
 
 //------------------------------------------------------------------
 nsresult
@@ -657,10 +666,12 @@ DocumentViewerImpl::GetContainer(nsISupports** aResult)
 
 NS_IMETHODIMP
 DocumentViewerImpl::Init(nsIWidget* aParentWidget,
-                         nsIDeviceContext* aDeviceContext,
                          const nsRect& aBounds)
 {
-  return InitInternal(aParentWidget, nsnull, aDeviceContext, aBounds, PR_TRUE, PR_FALSE);
+  nsresult rv = CreateDeviceContext(aParentWidget);
+  NS_ENSURE_SUCCESS(rv, rv);
+  
+  return InitInternal(aParentWidget, nsnull, aBounds, PR_TRUE, PR_FALSE);
 }
 
 nsresult
@@ -794,7 +805,6 @@ DocumentViewerImpl::InitPresentationStuff(PRBool aDoInitialReflow, PRBool aReena
 nsresult
 DocumentViewerImpl::InitInternal(nsIWidget* aParentWidget,
                                  nsISupports *aState,
-                                 nsIDeviceContext* aDeviceContext,
                                  const nsRect& aBounds,
                                  PRBool aDoCreation,
                                  PRBool aInPrintPreview,
@@ -805,8 +815,6 @@ DocumentViewerImpl::InitInternal(nsIWidget* aParentWidget,
   nsresult rv = NS_OK;
   NS_ENSURE_TRUE(mDocument, NS_ERROR_NULL_POINTER);
 
-  mDeviceContext = aDeviceContext;
-
   PRBool makeCX = PR_FALSE;
   if (aDoCreation) {
     if (aParentWidget && !mPresContext) {
@@ -819,7 +827,7 @@ DocumentViewerImpl::InitInternal(nsIWidget* aParentWidget,
             new nsPresContext(mDocument, nsPresContext::eContext_Galley);
       NS_ENSURE_TRUE(mPresContext, NS_ERROR_OUT_OF_MEMORY);
 
-      nsresult rv = mPresContext->Init(aDeviceContext); 
+      nsresult rv = mPresContext->Init(mDeviceContext); 
       if (NS_FAILED(rv)) {
         mPresContext = nsnull;
         return rv;
@@ -1242,8 +1250,7 @@ DocumentViewerImpl::Open(nsISupports *aState, nsISHEntry *aSHEntry)
   nsRect bounds;
   mWindow->GetBounds(bounds);
 
-  nsresult rv = InitInternal(mParentWidget, aState, mDeviceContext, bounds,
-                             PR_FALSE, PR_FALSE);
+  nsresult rv = InitInternal(mParentWidget, aState, bounds, PR_FALSE, PR_FALSE);
   NS_ENSURE_SUCCESS(rv, rv);
 
   if (mDocument)
@@ -1872,8 +1879,6 @@ DocumentViewerImpl::Show(void)
   }
 
   if (mDocument && !mPresShell && !mWindow) {
-    nsresult rv;
-
     nsCOMPtr<nsIBaseWindow> base_win(do_QueryReferent(mContainer));
     NS_ENSURE_TRUE(base_win, NS_ERROR_UNEXPECTED);
 
@@ -1881,7 +1886,8 @@ DocumentViewerImpl::Show(void)
     NS_ENSURE_TRUE(mParentWidget, NS_ERROR_UNEXPECTED);
     mParentWidget->Release(); // GetParentWidget AddRefs, but mParentWidget is weak
 
-    mDeviceContext = mParentWidget->GetDeviceContext();
+    nsresult rv = CreateDeviceContext(mParentWidget);
+    NS_ENSURE_SUCCESS(rv, rv);
 
     // Create presentation context
     NS_ASSERTION(!mPresContext, "Shouldn't have a prescontext if we have no shell!");
@@ -2271,6 +2277,18 @@ DocumentViewerImpl::MakeWindow(const nsSize& aSize)
   return rv;
 }
 
+nsresult
+DocumentViewerImpl::CreateDeviceContext(nsIWidget* aWidget)
+{
+  NS_PRECONDITION(!mDeviceContext, "How come we're calling this?");
+  if (aWidget) {
+    mDeviceContext = do_CreateInstance(kDeviceContextCID);
+    NS_ENSURE_TRUE(mDeviceContext, NS_ERROR_FAILURE);
+    mDeviceContext->Init(aWidget->GetNativeData(NS_NATIVE_WIDGET));
+  }
+  return NS_OK;
+}
+
 // Return the selection for the document. Note that text fields have their
 // own selection, which cannot be accessed with this method. Use
 // mPresShell->GetSelectionForCopy() instead.
@@ -4105,7 +4123,7 @@ NS_IMETHODIMP DocumentViewerImpl::SetPageMode(PRBool aPageMode, nsIPrintSettings
     nsresult rv = mPresContext->Init(mDeviceContext);
     NS_ENSURE_SUCCESS(rv, rv);
   }
-  InitInternal(mParentWidget, nsnull, mDeviceContext, bounds, PR_TRUE, PR_FALSE, PR_FALSE);
+  InitInternal(mParentWidget, nsnull, bounds, PR_TRUE, PR_FALSE, PR_FALSE);
   mViewManager->EnableRefresh(NS_VMREFRESH_NO_SYNC);
 
   Show();

layout/base/tests/Makefile.in

@@ -93,6 +93,7 @@ _TEST_FILES =	\
 		test_bug420499.xul \
 		test_bug423523.html \
 		test_bug445810.html \
+		test_bug449781.html \
 		$(NULL)
 # test_bug396024.html is currently disabled because it interacts badly with
 # the "You can't print-preview while the page is loading" dialog.

layout/base/tests/test_bug449781.html

@@ -0,0 +1,71 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=449781
+-->
+<head>
+  <title>Test for Bug 449781</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/WindowSnapshot.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=449781">Mozilla Bug 449781</a>
+<p id="display">Canary</p>
+<iframe src="about:blank" id="ourFrame" style="visibility: hidden">
+</iframe>
+</div>
+<pre id="test">
+<script class="testbody" type="text/javascript">
+var s1, s2, s3, s4;
+
+/** Test for Bug 449781 **/
+SimpleTest.waitForExplicitFinish();
+addLoadEvent(function() {
+  s1 = snapshotWindow(window);
+
+  $("ourFrame").style.display = "none";
+  is($("ourFrame").offsetWidth, 0, "Unexpected width after hiding");
+  $("ourFrame").style.display = "";
+  is($("ourFrame").clientWidth, 300, "Unexpected width after showing");
+
+  s2 = snapshotWindow(window);
+
+  var equal, str1, str2;
+  [equal, str1, str2] = compareSnapshots(s1, s2);
+  ok(equal, "Show/hide should have no effect",
+     "got " + str1 + " but expected " + str2);
+
+  netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect');
+  var viewer =
+    $("ourFrame").contentWindow
+                 .QueryInterface(Components.interfaces.nsIInterfaceRequestor)
+                 .getInterface(Components.interfaces.nsIWebNavigation)
+                 .QueryInterface(Components.interfaces.nsIDocShell)
+                 .contentViewer
+                 .QueryInterface(Components.interfaces.nsIMarkupDocumentViewer);
+  viewer.fullZoom = 2;
+  
+  s3 = snapshotWindow(window);
+
+  [equal, str1, str2] = compareSnapshots(s1, s3);
+  ok(equal, "Zoom should have no effect",
+     "got " + str1 + " but expected " + str2);
+
+  $("display").style.display = "none";
+
+  s4 = snapshotWindow(window);
+  [equal, str1, str2] = compareSnapshots(s3, s4);
+  ok(!equal, "Should be able to see the canary");
+
+  SimpleTest.finish();
+});
+
+
+
+</script>
+</pre>
+</body>
+</html>
+

testing/mochitest/tests/SimpleTest/Makefile.in

@@ -51,6 +51,7 @@ _SIMPLETEST_FILES =	MozillaFileLogger.js \
 			TestRunner.js \
 			setup.js \
 			EventUtils.js \
+			WindowSnapshot.js \
 			$(NULL)
 
 libs:: $(_SIMPLETEST_FILES)

testing/mochitest/tests/SimpleTest/WindowSnapshot.js

@@ -0,0 +1,47 @@
+netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect');
+
+var gWindowSnapshotCompareHelper;
+
+try {
+  gWindowSnapshotCompareHelper =
+    Components.classes["@mozilla.org/reftest-helper;1"]
+              .getService(Components.interfaces.nsIReftestHelper);
+} catch (e) {
+  gWindowSnapshotCompareHelper = null;
+}
+
+function snapshotWindow(win) {
+  var el = document.createElementNS("http://www.w3.org/1999/xhtml", "canvas");
+  el.width = win.innerWidth;
+  el.height = win.innerHeight;
+
+  // drawWindow requires privileges
+  netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect');
+  
+  el.getContext("2d").drawWindow(win, win.scrollX, win.scrollY,
+				 win.innerWidth, win.innerHeight,
+				 "rgb(255,255,255)");
+  return el;
+}
+
+// If the two snapshots aren't equal, returns their serializations as data URIs.
+function compareSnapshots(s1, s2) {
+  netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect');
+
+  var s1Str, s2Str;
+  var equal = false;
+  if (gWindowSnapshotCompareHelper) {
+    equal = (gWindowSnapshotCompareHelper.compareCanvas(s1, s2) == 0);
+  }
+
+  if (!equal) {
+    s1Str = s1.toDataURL();
+    s2Str = s2.toDataURL();
+
+    if (!gWindowSnapshotCompareHelper) {
+      equal = (s1Str == s2Str);
+    }
+  }
+
+  return [equal, s1Str, s2Str];
+}