Qt: Fix several debugger hangs and odd cases (fixes #691)

src/gba/gba.c

@@ -268,6 +268,7 @@ static void GBAProcessEvents(struct ARMCore* cpu) {
 	}
 }
 
+#ifdef USE_DEBUGGERS
 void GBAAttachDebugger(struct GBA* gba, struct mDebugger* debugger) {
 	gba->debugger = (struct ARMDebugger*) debugger->platform;
 	gba->debugger->setSoftwareBreakpoint = _setSoftwareBreakpoint;
@@ -277,10 +278,13 @@ void GBAAttachDebugger(struct GBA* gba, struct mDebugger* debugger) {
 }
 
 void GBADetachDebugger(struct GBA* gba) {
-	gba->debugger = 0;
-	ARMHotplugDetach(gba->cpu, CPU_COMPONENT_DEBUGGER);
-	gba->cpu->components[CPU_COMPONENT_DEBUGGER] = 0;
+	if (gba->debugger) {
+		ARMHotplugDetach(gba->cpu, CPU_COMPONENT_DEBUGGER);
+	}
+	gba->cpu->components[CPU_COMPONENT_DEBUGGER] = NULL;
+	gba->debugger = NULL;
 }
+#endif
 
 bool GBALoadMB(struct GBA* gba, struct VFile* vf) {
 	GBAUnloadROM(gba);

src/platform/qt/DebuggerConsoleController.cpp

@@ -38,7 +38,14 @@ void DebuggerConsoleController::enterLine(const QString& line) {
 	m_cond.wakeOne();
 }
 
+void DebuggerConsoleController::detach() {
+	m_lines.append(QString());
+	m_cond.wakeOne();
+	DebuggerController::detach();
+}
+
 void DebuggerConsoleController::attachInternal() {
+	m_history.clear();
 	mCore* core = m_gameController->thread()->core;
 	CLIDebuggerAttachBackend(&m_cliDebugger, &m_backend.d);
 	CLIDebuggerAttachSystem(&m_cliDebugger, core->cliDebuggerSystem(core));
@@ -61,6 +68,8 @@ void DebuggerConsoleController::init(struct CLIDebuggerBackend* be) {
 void DebuggerConsoleController::deinit(struct CLIDebuggerBackend* be) {
 	Backend* consoleBe = reinterpret_cast<Backend*>(be);
 	DebuggerConsoleController* self = consoleBe->self;
+	self->m_lines.append(QString());
+	self->m_cond.wakeOne();
 }
 
 const char* DebuggerConsoleController::readLine(struct CLIDebuggerBackend* be, size_t* len) {
@@ -72,6 +81,9 @@ const char* DebuggerConsoleController::readLine(struct CLIDebuggerBackend* be, s
 		self->m_cond.wait(&self->m_mutex);
 	}
 	self->m_last = self->m_lines.takeFirst().toUtf8();
+	if (self->m_last.isEmpty()) {
+		self->m_last = "\n";
+	}
 	*len = self->m_last.size();
 	return self->m_last.constData();
 
@@ -89,7 +101,7 @@ const char* DebuggerConsoleController::historyLast(struct CLIDebuggerBackend* be
 	GameController::Interrupter interrupter(self->m_gameController, true);
 	QMutexLocker lock(&self->m_mutex);
 	if (self->m_history.isEmpty()) {
-		return nullptr;
+		return "\n";
 	}
 	self->m_last = self->m_history.last().toUtf8();
 	return self->m_last.constData();

src/platform/qt/DebuggerConsoleController.h

@@ -30,6 +30,7 @@ signals:
 
 public slots:
 	void enterLine(const QString&);
+	virtual void detach() override;
 
 protected:
 	virtual void attachInternal() override;

src/platform/qt/GameController.cpp

@@ -623,6 +623,7 @@ void GameController::closeGame() {
 		return;
 	}
 
+	setDebugger(nullptr);
 	if (mCoreThreadIsPaused(&m_threadContext)) {
 		mCoreThreadUnpause(&m_threadContext);
 	}