Bug 334991 - Variables view: Add history with recent expressions to the
details pane

Change-Id: I416887ef8a614e9013d6479e83809f17300dba14
diff --git a/org.eclipse.jdt.debug.ui/ui/org/eclipse/jdt/internal/debug/ui/variables/JavaVariablesDetailPane.java b/org.eclipse.jdt.debug.ui/ui/org/eclipse/jdt/internal/debug/ui/variables/JavaVariablesDetailPane.java
index 6c2fe64..b4612a0 100644
--- a/org.eclipse.jdt.debug.ui/ui/org/eclipse/jdt/internal/debug/ui/variables/JavaVariablesDetailPane.java
+++ b/org.eclipse.jdt.debug.ui/ui/org/eclipse/jdt/internal/debug/ui/variables/JavaVariablesDetailPane.java
@@ -110,10 +110,12 @@
 
 			@Override
 			public void focusGained(FocusEvent e) {
+				fValue = null;
 				try {
-					fValue = fVariable.getValue();
+					if (fVariable != null) {
+						fValue = fVariable.getValue();
+					}
 				} catch (DebugException ex) {
-					fValue = null;
 				}
 			}
 		};