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/WizardArchiveFileResourceImportPage1.java
*/
    private TarFile getSpecifiedTarSourceFile(String fileName) {
        if (fileName.length() == 0)
            return null;
        try {
            return new TarFile(fileName);
        } catch (TarException e) {
        	displayErrorDialog(DataTransferMessages.TarImport_badFormat);
        } catch (IOException e) {
            displayErrorDialog(DataTransferMessages.ZipImport_couldNotRead);
        }
        sourceNameField.setFocus();
        return null;
    }
    /**
     *	Open a FileDialog so that the user can specify the source
     *	file to import from
     */
    protected void handleSourceBrowseButtonPressed() {
        String selectedFile = queryZipFileToImport();
        if (selectedFile != null) {
            
            if (!selectedFile.equals(sourceNameField.getText())
					&& validateSourceFile(selectedFile)) {
                setSourceName(selectedFile);
                selectionGroup.setFocus();
            }
        }
    }
    /**