Bug 310446 [LinkedResources] "Preferences > Linked Resources > New..." should not show "Variable..."
I20100425-2000 "Preferences > Linked Resources": The "New..." and "Edit..." dialogs should not show the "Variable..." button. When I select a variable, the "New Variable" dialog show an error (Path must be absolute.), and when I try to click "Extend...", nothing happens.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/PathVariablesGroup.java
this.variableType = variableType;
        pathVariableManager = ResourcesPlugin.getWorkspace()
                .getPathVariableManager();
        removedVariableNames = new HashSet();
        tempPathVariables = new TreeMap();
        
        initTemporaryState();
    }
    /**
     * Creates a new PathVariablesGroup.
     *
     * @param multiSelect create a multi select tree
     * @param variableType the type of variables that are displayed in 
     * 	the widget group. <code>IResource.FILE</code> and/or <code>IResource.FOLDER</code>
     * 	logically ORed together.
     * @param selectionListener listener notified when the selection changes
     * 	in the variables list.
     */
    public PathVariablesGroup(boolean multiSelect, int variableType,
            Listener selectionListener) {
        this(multiSelect, variableType);
        this.selectionListener = selectionListener;
    }
    /**
     * Opens a dialog for creating a new variable.
     */
    private void addNewVariable() {
        
        PathVariableDialog dialog = new PathVariableDialog(shell,
                PathVariableDialog.NEW_VARIABLE, variableType,