hgweb: add parents to json-log (issue5074) Entries prepared in webutil.changelistentry() skip showing parents in the trivial case when there's only one parent and it's the previous revision. This doesn't work well for the json-log template, which is supposed to just dump raw data in an easy-to-parse format, so let's provide all parents as another keyword: allparents. Using a lambda function here means that the performance of templates that don't use allparents won't be affected (see 41957e50e109).