Reversing patches

You can reverse a patch if you have finished testing it, or if you want to see whether a problem has been introduced by a particular patch. You should also reverse a patch prior to adding a newer, updated version of the same patch. To reverse the patch, use the patch command with the -R option:

If you've applied more than one patch, or want to revert changes you've made to Drupal core yourself, a useful command is:

This creates a diff of all changes to core and reverses it, leaving you with a clean copy of HEAD. If the reverse is successful, you'll see a list of the core files that were reverted. If there's nothing to revert, i.e., you've already got a clean copy of HEAD, you might instead see a message similar to 'only garbage was found in the patch'.

Another way of reverting to a clean copy of core is by using:

... but CVS will automatically backup the changed files as .#>old-name<. To remove those, use: