Debugger: Clean up GdbEngine member data on finish

Restarting with cached outdated information is problematic.

Change-Id: I396da2fef96a161c1ab150134b8e65a758a16d58
Task-number: QTCREATORBUG-16355
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/debugger/debuggerengine.cpp

@@ -1280,6 +1280,7 @@ void DebuggerEngine::setState(DebuggerState state, bool forced)
             bp.notifyBreakpointReleased();
         DebuggerToolTipManager::deregisterEngine(this);
         d->m_memoryAgent.handleDebuggerFinished();
+        prepareForRestart();
     }
 
     showMessage(msg, LogDebug);

src/plugins/debugger/debuggerengine.h

@@ -201,6 +201,7 @@ public:
     virtual void selectWatchData(const QByteArray &iname);
 
     virtual void startDebugger(DebuggerRunControl *runControl);
+    virtual void prepareForRestart() {}
 
     virtual void watchPoint(const QPoint &);
 

src/plugins/debugger/gdb/gdbengine.cpp

@@ -4300,6 +4300,14 @@ void GdbEngine::notifyInferiorSetupFailed()
     DebuggerEngine::notifyInferiorSetupFailed();
 }
 
+void GdbEngine::prepareForRestart()
+{
+    m_rerunPending = false;
+    m_commandsDoneCallback = 0;
+    m_commandForToken.clear();
+    m_flagsForToken.clear();
+}
+
 void GdbEngine::handleInferiorPrepared()
 {
     const DebuggerRunParameters &rp = runParameters();

src/plugins/debugger/gdb/gdbengine.h

@@ -72,6 +72,7 @@ private: ////////// General Interface //////////
 
     virtual void handleGdbStartFailed();
     void notifyInferiorSetupFailed() override;
+    void prepareForRestart() override;
 
     bool hasCapability(unsigned) const override;
     void detachDebugger() override;