Bug 35265 NPE in classpath variables page
Build: I-20030317 I was switching back and forth between target platform and classpath variables preference pages, changing values on target platform page and seeing if changes are reflected on classpath variables page. At some point, I got the following null pointer: java.lang.NullPointerException at org.eclipse.jdt.internal.ui.wizards.buildpaths.CPVariableElementLabelProvider.ge tImage(CPVariableElementLabelProvider.java:55) at org.eclipse.jface.viewers.TableViewer.doUpdateItem(TableViewer.java:202) at org.eclipse.jface.viewers.StructuredViewer$UpdateItemSafeRunnable.run (StructuredViewer.java:119) at org.eclipse.core.internal.runtime.InternalPlatform.run (InternalPlatform.java:867) at org.eclipse.core.runtime.Platform.run(Platform.java:413) at org.eclipse.jface.viewers.StructuredViewer.updateItem (StructuredViewer.java:1271) at org.eclipse.jface.viewers.TableViewer.internalRefresh(TableViewer.java:454) at org.eclipse.jface.viewers.TableViewer.internalRefresh(TableViewer.java:431) at org.eclipse.jface.viewers.StructuredViewer$7.run(StructuredViewer.java:861) at org.eclipse.jface.viewers.StructuredViewer.preservingSelection (StructuredViewer.java:801) at org.eclipse.jface.viewers.StructuredViewer.refresh(StructuredViewer.java:859) at org.eclipse.jface.viewers.StructuredViewer.refresh(StructuredViewer.java:821) at org.eclipse.jdt.internal.ui.wizards.dialogfields.ListDialogField.refresh (ListDialogField.java:739) at org.eclipse.jdt.internal.ui.wizards.buildpaths.VariableBlock.refresh (VariableBlock.java:406) at org.eclipse.jdt.internal.ui.preferences.ClasspathVariablesPreferencePage.setVisi ble(ClasspathVariablesPreferencePage.java:80) at org.eclipse.jface.preference.PreferenceDialog.showPage (PreferenceDialog.java:1064) at org.eclipse.jface.preference.PreferenceDialog$9.run (PreferenceDialog.java:496)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/VariableBlock.java
JavaRuntime.JRESRCROOT_VARIABLE,
		};
	}
	
	public Control createContents(Composite parent) {
		Composite composite= new Composite(parent, SWT.NONE);
		LayoutUtil.doDefaultLayout(composite, new DialogField[] { fVariablesList }, true, 0, 0);
		LayoutUtil.setHorizontalGrabbing(fVariablesList.getListControl(null));
		
		fControl= composite;
		return composite;
	}
	
	public void addDoubleClickListener(IDoubleClickListener listener) {
		fVariablesList.getTableViewer().addDoubleClickListener(listener);
	}
	
	public void addSelectionChangedListener(ISelectionChangedListener listener) {
		fVariablesList.getTableViewer().addSelectionChangedListener(listener);
	}	
		
	
	private Shell getShell() {
		if (fControl != null) {
			return fControl.getShell();
		}
		return JavaPlugin.getActiveWorkbenchShell();
	}
	
	private class VariablesAdapter implements IDialogFieldListener, IListAdapter {