Get snippet changes between versions

Returns the diff of the specified commit against its first parent.

Note that this resource is different in functionality from the patch resource.

The differences between a diff and a patch are:

• patches have a commit header with the username, message, etc
• diffs support the optional path=foo/bar.py query param to filter the diff to just that one file diff (not supported for patches)
• for a merge, the diff will show the diff between the merge commit and its first parent (identical to how PRs work), while patch returns a response containing separate patches for each commit on the second parent's ancestry, up to the oldest common ancestor (identical to its reachability).

Note that the character encoding of the contents of the diff is unspecified as Git does not track this, making it hard for Bitbucket to reliably determine this.