[[plugin/recentchangesdiff]] causes rendering to segfault if a commit removes a lot of contents. I removed close to 400 files, total size of about 950Kb in a single commit and now `ikiwiki` segfaults on refresh and rebuild:

    [...]
    rendering recentchanges.mdwn
    [1]    5541 segmentation fault  ikiwiki --verbose --setup ikiwiki.setup --refresh

If I disable the plugin, the segfault does not happen, but I have to remove `wc/recentchanges/*` or else it will crash just as well.

This is reproducible, but I cannot provide the source code.