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/ide/dialogs/PathVariableSelectionDialog.java
super.okPressed();
    }
    /**
     * Sets the dialog result to the concatenated variable name and extension.
     * 
     * @param variable variable selected in the variables list and extended
     * 	by <code>extensionFile</code>
     * @param extensionFile file selected to extend the variable.
     */
    private void setExtensionResult(
            PathVariablesGroup.PathVariableElement variable, IFileStore extensionFile) {
        IPath extensionPath = new Path(extensionFile.toString());
		IPath selectionPath = variable.path;
		if (currentResource != null)
			selectionPath = URIUtil.toPath(currentResource.getPathVariableManager().resolveURI(URIUtil.toURI(selectionPath)));
		int matchCount = extensionPath.matchingFirstSegments(selectionPath);
        IPath resultPath = new Path(variable.name);
        extensionPath = extensionPath.removeFirstSegments(matchCount);
        resultPath = resultPath.append(extensionPath);
		setSelectionResult(new String[] { resultPath.toPortableString() });
    }
    /**
     * Updates the enabled state of the Extend button based on the 
     * current variable selection.
     */
    private void updateExtendButtonState() {
        PathVariablesGroup.PathVariableElement[] selection = pathVariablesGroup
                .getSelection();
        Button extendButton = getButton(EXTEND_ID);
        if (extendButton == null) {