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
operation.setContext(getShell());
        return executeImportOperation(operation);
    }
    /**
     * Initializes the specified operation appropriately.
     */
    protected void initializeOperation(ImportOperation op) {
        op.setCreateContainerStructure(createContainerStructureButton
                .getSelection());
        op.setOverwriteResources(overwriteExistingResourcesCheckbox
                .getSelection());
    }
    /**
     * Returns whether the extension provided is an extension that
     * has been specified for export by the user.
     *
     * @param extension the resource name
     * @return <code>true</code> if the resource name is suitable for export based 
     *   upon its extension
     */
    protected boolean isExportableExtension(String extension) {
        if (selectedTypes == null) 
            return true;
        Iterator itr = selectedTypes.iterator();
        while (itr.hasNext()) {
            if (extension.equalsIgnoreCase((String) itr.next()))
                return true;
        }
        return false;
    }