Currently, new comments are named with an incrementing ID (comment_N). So if a wiki has multiple disconnected servers, and comments are made to the same page on both, merging is guaranteed to result in conflicts.
I propose avoiding such merge problems by naming a comment with a sha1sum of its (full) content. Keep the incrementing ID too, so there is an -ordering. And so duplicate comments are allowed..) So, "comment_N_SHA1".
Note: The comment body will need to use meta title in the case where no title is specified, to retain the current behavior of the default title being "comment N".
I had to use md5sums, as sha1sum perl module may not be available and I didn't want to drag it in. But I think that's ok; this doesn't need to be cryptographically secure and even the chances of being able to purposefully cause a md5 collision and thus an undesired merge conflict are quite low since it modifies the input text and adds a date stamp to it.