### Eclipse Workspace Patch 1.0
#P org.eclipse.compare
Index: compare/org/eclipse/compare/internal/CompareEditor.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.compare/plugins/org.eclipse.compare/compare/org/eclipse/compare/internal/CompareEditor.java,v
retrieving revision 1.79
diff -u -r1.79 CompareEditor.java
--- compare/org/eclipse/compare/internal/CompareEditor.java	24 Apr 2009 14:58:50 -0000	1.79
+++ compare/org/eclipse/compare/internal/CompareEditor.java	29 Apr 2009 15:57:14 -0000
@@ -447,6 +447,8 @@
 				if (getSite().getSelectionProvider() == null)
 					getSite().setSelectionProvider(new CompareEditorSelectionProvider());
 				fControl= ci.createContents(fPageBook);
+				if (fControl == null)
+					return; // closed while creating
 				fPageBook.showPage(fControl);
 				PlatformUI.getWorkbench().getHelpSystem().setHelp(fControl, ICompareContextIds.COMPARE_EDITOR);
 				if (isActive()) {
Index: compare/org/eclipse/compare/internal/CompareContentViewerSwitchingPane.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.compare/plugins/org.eclipse.compare/compare/org/eclipse/compare/internal/CompareContentViewerSwitchingPane.java,v
retrieving revision 1.5
diff -u -r1.5 CompareContentViewerSwitchingPane.java
--- compare/org/eclipse/compare/internal/CompareContentViewerSwitchingPane.java	17 Apr 2009 12:39:12 -0000	1.5
+++ compare/org/eclipse/compare/internal/CompareContentViewerSwitchingPane.java	29 Apr 2009 15:57:14 -0000
@@ -130,6 +130,8 @@
 
 	public void setInput(Object input) {
 		super.setInput(input);
+		if (getViewer() == null || !Utilities.okToUse(getViewer().getControl()))
+			return;
 		ViewerDescriptor[] vd = CompareUIPlugin.getDefault()
 				.findContentViewerDescriptor(getViewer(), getInput(),
 						getCompareConfiguration());
Index: compare/org/eclipse/compare/internal/CompareStructureViewerSwitchingPane.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.compare/plugins/org.eclipse.compare/compare/org/eclipse/compare/internal/CompareStructureViewerSwitchingPane.java,v
retrieving revision 1.1
diff -u -r1.1 CompareStructureViewerSwitchingPane.java
--- compare/org/eclipse/compare/internal/CompareStructureViewerSwitchingPane.java	17 Apr 2009 12:39:12 -0000	1.1
+++ compare/org/eclipse/compare/internal/CompareStructureViewerSwitchingPane.java	29 Apr 2009 15:57:14 -0000
@@ -130,6 +130,8 @@
 
 	public void setInput(Object input) {
 		super.setInput(input);
+		if (getViewer() == null || !Utilities.okToUse(getViewer().getControl()))
+			return;
 		ViewerDescriptor[] vd = null;
 		if (getInput() instanceof ICompareInput) {
 			vd = CompareUIPlugin.getDefault().findStructureViewerDescriptor(
Index: compare/org/eclipse/compare/CompareEditorInput.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.compare/plugins/org.eclipse.compare/compare/org/eclipse/compare/CompareEditorInput.java,v
retrieving revision 1.110
diff -u -r1.110 CompareEditorInput.java
--- compare/org/eclipse/compare/CompareEditorInput.java	24 Apr 2009 14:58:50 -0000	1.110
+++ compare/org/eclipse/compare/CompareEditorInput.java	29 Apr 2009 15:57:14 -0000
@@ -543,7 +543,10 @@
 		fComposite.layout();
 
 		feedInput();
-	
+		
+		if (!Utilities.okToUse(fComposite) || !Utilities.okToUse(fComposite))
+			return fComposite; // null
+		
 		fComposite.addDisposeListener(new DisposeListener() {
 			public void widgetDisposed(DisposeEvent e) {
 				if (!(getWorkbenchPart() instanceof CompareEditor))
@@ -748,11 +751,15 @@
 						Object input= fStructureInputPane.getInput();
 						if (input != null)
 							internalSetContentPaneInput(input);
+						if (!Utilities.okToUse(fStructurePane1) || !Utilities.okToUse(fStructurePane2))
+							return;
 						fStructurePane2.setInput(null); // clear downstream pane
 						fStructurePane1.setInput(null);
 					} else {
 						Object input= getElement(selection);
 						internalSetContentPaneInput(input);
+						if (!Utilities.okToUse(fStructurePane1) || !Utilities.okToUse(fStructurePane2))
+							return;						
 						if (structureCompareOnSingleClick() || hasUnusableContentViewer())
 							fStructurePane1.setInput(input);
 						fStructurePane2.setInput(null); // clear downstream pane
Index: compare/org/eclipse/compare/CompareViewerSwitchingPane.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.compare/plugins/org.eclipse.compare/compare/org/eclipse/compare/CompareViewerSwitchingPane.java,v
retrieving revision 1.34
diff -u -r1.34 CompareViewerSwitchingPane.java
--- compare/org/eclipse/compare/CompareViewerSwitchingPane.java	17 Mar 2009 12:08:26 -0000	1.34
+++ compare/org/eclipse/compare/CompareViewerSwitchingPane.java	29 Apr 2009 15:57:14 -0000
@@ -11,13 +11,19 @@
 package org.eclipse.compare;
 
 import org.eclipse.compare.contentmergeviewer.IFlushable;
-import org.eclipse.compare.internal.*;
+import org.eclipse.compare.internal.CompareMessages;
+import org.eclipse.compare.internal.NullViewer;
+import org.eclipse.compare.internal.Utilities;
 import org.eclipse.compare.structuremergeviewer.ICompareInput;
-import org.eclipse.jface.viewers.*;
+import org.eclipse.jface.viewers.ISelection;
+import org.eclipse.jface.viewers.StructuredViewer;
+import org.eclipse.jface.viewers.Viewer;
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.graphics.Image;
-import org.eclipse.swt.widgets.*;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Display;
 
 import com.ibm.icu.text.MessageFormat;
 
@@ -269,6 +275,9 @@
 		// set input
 		fViewer.setInput(input);
 
+		if (getViewer() == null || !Utilities.okToUse(getViewer().getControl()))
+			return;
+
 		Image image= null;
 		if (!(fViewer instanceof NullViewer) && input instanceof ICompareInput)
 			image= ((ICompareInput)input).getImage();