Bug 564224 - Add null guard

getShell() might return null.

Change-Id: I9b7361d6fbbe711c9113048129587104113b9531
Signed-off-by: Karsten Thoms <karsten.thoms@karakun.com>
diff --git a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchWindow.java b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchWindow.java
index e4c9624..b1cd69b 100644
--- a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchWindow.java
+++ b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchWindow.java
@@ -2998,7 +2998,10 @@
 		MTrimBar topTrim = getTopTrim();
 		if (topTrim != null) {
 			topTrim.setVisible(isToolbarVisible());
-			getShell().layout();
+			Shell shell = getShell();
+			if (shell != null && !shell.isDisposed()) {
+				shell.layout();
+			}
 		}
 	}