Also lock fAboutWindow before Quit()ting in other apps

src/apps/activitymonitor/ActivityView.cpp

@@ -602,7 +602,7 @@ ActivityView::~ActivityView()
 	delete fSystemInfoHandler;
 
 	// replicant deleted, destroy the about window
-	if (fAboutWindow != NULL)
+	if (fAboutWindow != NULL && fAboutWindow->Lock())
 		fAboutWindow->Quit();
 }
 

src/apps/deskcalc/CalcView.cpp

@@ -185,7 +185,7 @@ CalcView::~CalcView()
 	free(fKeypadDescription);
 
 	// replicant deleted, destroy the about window
-	if (fAboutWindow != NULL)
+	if (fAboutWindow != NULL && fAboutWindow->Lock())
 		fAboutWindow->Quit();
 }
 

src/apps/networkstatus/NetworkStatusView.cpp

@@ -139,7 +139,7 @@ NetworkStatusView::NetworkStatusView(BMessage* archive)
 
 NetworkStatusView::~NetworkStatusView()
 {
-	if (fAboutWindow != NULL)
+	if (fAboutWindow != NULL && fAboutWindow->Lock())
 		fAboutWindow->Quit();
 }
 

src/apps/processcontroller/ProcessController.cpp

@@ -206,7 +206,7 @@ ProcessController::~ProcessController()
 	gPCView = NULL;
 
 	// replicant deleted, destroy the about window
-	if (fAboutWindow != NULL)
+	if (fAboutWindow != NULL && fAboutWindow->Lock())
 		fAboutWindow->Quit();
 }
 

src/apps/workspaces/Workspaces.cpp

@@ -374,7 +374,7 @@ WorkspacesView::WorkspacesView(BMessage* archive)
 
 WorkspacesView::~WorkspacesView()
 {
-	if (fAboutWindow != NULL)
+	if (fAboutWindow != NULL && fAboutWindow->Lock())
 		fAboutWindow->Quit();
 }