Bug 97523 [Import/Export] Get overwrite prompt before no resources selected prompt
3.1 RC1 - File > Export > Archive - clear any selected resources - enter an archive file name where the file already exists - Finish - it prompts to overwrite the file; choose Yes - it says "There are no resources currently selected for export" (OK) Should get the "no resources" prompt first, and not bother with the second one. Should check the other export wizards too.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/WizardFileSystemResourceImportPage1.java
* Returns a content provider for <code>FileSystemElement</code>s that returns 
     * only files as children.
     */
    protected ITreeContentProvider getFileProvider() {
        return new WorkbenchContentProvider() {
            public Object[] getChildren(Object o) {
                if (o instanceof MinimizedFileSystemElement) {
                    MinimizedFileSystemElement element = (MinimizedFileSystemElement) o;
                    return element.getFiles(
                            FileSystemStructureProvider.INSTANCE).getChildren(
                            element);
                }
                return new Object[0];
            }
        };
    }
    /**
     *	Answer the root FileSystemElement that represents the contents of
     *	the currently-specified source.  If this FileSystemElement is not
     *	currently defined then create and return it.
     */
    protected MinimizedFileSystemElement getFileSystemTree() {
        File sourceDirectory = getSourceDirectory();
        if (sourceDirectory == null)
            return null;
        return selectFiles(sourceDirectory,
                FileSystemStructureProvider.INSTANCE);
    }
    /**
     * Returns a content provider for <code>FileSystemElement</code>s that returns