Bug 30291 SearchUsagesInFileAction should show dialog in case of failures
Build I20030122 SearchUsagesInFileAction should show a dialog in failure/error cases (e.g. code resolve fails).
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/search/SearchUsagesInFileAction.java
public boolean visit(SimpleName node) {
			match(node, fUsages);
			return super.visit(node);
		}
		public boolean visit(Assignment node) {
			Expression lhs= node.getLeftHandSide();
			Name name= getName(lhs);
			if (name != null) 
				match(name, fWriteUsages);	
			lhs.accept(this);
			node.getRightHandSide().accept(this);
			return false;
		}
		
		public boolean visit(SingleVariableDeclaration node) {
			if (node.getInitializer() != null)
				match(node.getName(), fWriteUsages);
			return super.visit(node);
		}
		public boolean visit(VariableDeclarationFragment node) {
			if (node.getInitializer() != null)
				match(node.getName(), fWriteUsages);
			return super.visit(node);
		}
		public boolean visit(PrefixExpression node) {
			PrefixExpression.Operator operator= node.getOperator();	
			if (operator == PrefixExpression.Operator.INCREMENT || operator == PrefixExpression.Operator.DECREMENT) {
				Expression operand= node.getOperand();
				Name name= getName(operand);
				if (name != null)