From 98f9c4f254f081202db3fb77e2438785c4cfaa9b Mon Sep 17 00:00:00 2001
From: Paul Gilbert <dreammaster@scummvm.org>
Date: Sun, 9 Feb 2020 11:06:20 -0800
Subject: [PATCH] ENGINES: Create a default debugger when needed if none is yet
 set

---
 backends/events/default/default-events.cpp |  2 +-
 engines/engine.cpp                         | 11 ++++++++++-
 engines/engine.h                           |  9 +++++++--
 3 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/backends/events/default/default-events.cpp b/backends/events/default/default-events.cpp
index a7c03f5dac7..929546e1fa7 100644
--- a/backends/events/default/default-events.cpp
+++ b/backends/events/default/default-events.cpp
@@ -112,7 +112,7 @@ bool DefaultEventManager::pollEvent(Common::Event &event) {
 			_currentKeyDown.ascii = Common::KEYCODE_BACKSPACE;
 
 		} else if (event.kbd.keycode == Common::KEYCODE_d && (_modifierState & Common::KBD_CTRL)) {
-			GUI::Debugger *debugger = g_engine->getDebugger();
+			GUI::Debugger *debugger = g_engine->getOrCreateDebugger();
 			if (debugger) {
 				debugger->attach();
 				debugger->onFrame();
diff --git a/engines/engine.cpp b/engines/engine.cpp
index d6e267fc8b7..ac6a01beb4b 100644
--- a/engines/engine.cpp
+++ b/engines/engine.cpp
@@ -86,7 +86,7 @@ static void defaultErrorHandler(const char *msg) {
 	// Unless this error -originated- within the debugger itself, we
 	// now invoke the debugger, if available / supported.
 	if (g_engine) {
-		GUI::Debugger *debugger = g_engine->getDebugger();
+		GUI::Debugger *debugger = g_engine->getOrCreateDebugger();
 
 #if defined(USE_TASKBAR)
 		g_system->getTaskbarManager()->notifyError();
@@ -760,6 +760,15 @@ bool Engine::shouldQuit() {
 	return (eventMan->shouldQuit() || eventMan->shouldRTL());
 }
 
+GUI::Debugger *Engine::getOrCreateDebugger() {
+	if (!_debugger)
+		// Create a bare-bones debugger. This is useful for engines without their own
+		// debugger when an error occurs
+		_debugger = new GUI::Debugger();
+
+	return _debugger;
+}
+
 /*
 EnginePlugin *Engine::getMetaEnginePlugin() const {
 	return EngineMan.findPlugin(ConfMan.get("engineid"));
diff --git a/engines/engine.h b/engines/engine.h
index 4172d126cca..65a325f74f9 100644
--- a/engines/engine.h
+++ b/engines/engine.h
@@ -174,8 +174,7 @@ public:
 	virtual void errorString(const char *buf_input, char *buf_output, int buf_output_size);
 
 	/**
-	 * Return the engine's debugger instance, if any. Used by error() to
-	 * invoke the debugger when a severe error is reported.
+	 * Return the engine's debugger instance, if any.
 	 */
 	virtual GUI::Debugger *getDebugger() { return _debugger; }
 
@@ -188,6 +187,12 @@ public:
 		_debugger = debugger;
 	}
 
+	/**
+	 * Return the engine's debugger instance, or create one if none is present.
+	 * Used by error() to invoke the debugger when a severe error is reported.
+	 */
+	GUI::Debugger *getOrCreateDebugger();
+
 	/**
 	 * Determine whether the engine supports the specified feature.
 	 */