avoid crash on shutdown with unprocessed events pending post SalDisplay dtor

1 files changed, 22 insertions, 13 deletions

diff --git a/vcl/unx/gtk/app/gtkdata.cxx b/vcl/unx/gtk/app/gtkdata.cxx
index dde909ff27f2..b68d02335ff1 100644
--- a/vcl/unx/gtk/app/gtkdata.cxx
+++ b/vcl/unx/gtk/app/gtkdata.cxx
@@ -859,28 +859,37 @@ extern "C"
 
 gboolean GtkXLib::userEventFn(gpointer data)
 {
-    gboolean bContinue;
+    gboolean bContinue = FALSE;
     GtkXLib *pThis = (GtkXLib *) data;
-    SalData *pSalData = GetSalData();
+    X11SalData *pSalData = GetX11SalData();
 
     pSalData->m_pInstance->GetYieldMutex()->acquire();
-    pThis->m_pGtkSalDisplay->EventGuardAcquire();
 
-    if( !pThis->m_pGtkSalDisplay->HasMoreEvents() )
+    const SalDisplay *pDisplay = pSalData->GetDisplay();
+    //GtkSalDisplay inherits from SalDisplay, SalDisplay's dtor deregisters
+    //itself from  SalData, so use presence of pDisplay here to detect that
+    //m_pGtkSalDisplay was destroyed by X11SalData::DeleteDisplay
+    if (pDisplay)
     {
-        if( pThis->m_pUserEvent )
+        OSL_ASSERT(pThis->m_pGtkSalDisplay == pDisplay);
+        pThis->m_pGtkSalDisplay->EventGuardAcquire();
+
+        if( !pThis->m_pGtkSalDisplay->HasMoreEvents() )
         {
-            g_source_unref (pThis->m_pUserEvent);
-            pThis->m_pUserEvent = NULL;
+            if( pThis->m_pUserEvent )
+            {
+                g_source_unref (pThis->m_pUserEvent);
+                pThis->m_pUserEvent = NULL;
+            }
+            bContinue = FALSE;
         }
-        bContinue = FALSE;
-    }
-    else
-        bContinue = TRUE;
+        else
+            bContinue = TRUE;
 
-    pThis->m_pGtkSalDisplay->EventGuardRelease();
+        pThis->m_pGtkSalDisplay->EventGuardRelease();
 
-    pThis->m_pGtkSalDisplay->DispatchInternalEvent();
+        pThis->m_pGtkSalDisplay->DispatchInternalEvent();
+    }
 
     pSalData->m_pInstance->GetYieldMutex()->release();