(svn r22228) -Fix (r22135)[FS#4546]: Do not resort town, industry and signs list directly in OnInvalidateData(). There might be a scheduled rebuild which needs execution first. So, only set a trigger for resorting.

src/group_gui.cpp

@@ -255,6 +255,9 @@ public:
 
 	virtual void OnInvalidateData(int data)
 	{
+		/* We can only set the trigger for resorting/rebuilding.
+		 * We cannot safely resort at this point, as there might be multiple scheduled invalidations,
+		 * and a rebuild needs to be done first though it is scheduled later. */
 		if (data == 0) {
 			this->vehicles.ForceRebuild();
 			this->groups.ForceRebuild();