Fix warning about object being leaked from update installer thread due to a missing autorelease pool

Allocate an NSAutoreleasePool in the updater thread and release it just
before the thread exits.

src/UpdateDialogCocoa.h

@@ -19,6 +19,9 @@ class UpdateDialogCocoa : public UpdateObserver
 		virtual void updateProgress(int percentage);
 		virtual void updateFinished();
 
+		static void* createAutoreleasePool();
+		static void releaseAutoreleasePool(void* data);
+
 	private:
 		UpdateDialogPrivate* d;
 };

src/UpdateDialogCocoa.mm

@@ -137,4 +137,14 @@ void UpdateDialogCocoa::updateFinished()
 	             waitUntilDone:false];
 }
 
+void* UpdateDialogCocoa::createAutoreleasePool()
+{
+	return [[NSAutoreleasePool alloc] init];
+}
+
+void UpdateDialogCocoa::releaseAutoreleasePool(void* arg)
+{
+	[(id)arg release];
+}
+
 

src/main.cpp

@@ -20,6 +20,12 @@ void runWithUi(int argc, char** argv, UpdateInstaller* installer);
 
 void runUpdaterThread(void* arg)
 {
+#ifdef PLATFORM_MAC
+	// create an autorelease pool to free any temporary objects
+	// created by Cocoa whilst handling notifications from the UpdateInstaller
+	void* pool = UpdateDialogCocoa::createAutoreleasePool();
+#endif
+
 	try
 	{
 		UpdateInstaller* installer = static_cast<UpdateInstaller*>(arg);
@@ -29,6 +35,10 @@ void runUpdaterThread(void* arg)
 	{
 		LOG(Error,"Unexpected exception " + std::string(ex.what()));
 	}
+
+#ifdef PLATFORM_MAC
+	UpdateDialogCocoa::releaseAutoreleasePool(pool);
+#endif
 }
 
 int main(int argc, char** argv)