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).

--- a/mercurial/templates/json/map	Mon Feb 29 17:46:06 2016 +0900
+++ b/mercurial/templates/json/map	Thu Mar 31 18:09:09 2016 +0800
@@ -11,7 +11,8 @@
   "desc": {desc|utf8|json},
   "bookmarks": [{join(bookmarks%changelistentryname, ", ")}],
   "tags": [{join(tags%changelistentryname, ", ")}],
-  "user": {author|utf8|json}
+  "user": {author|utf8|json},
+  "parents": [{join(allparents%changesetparent, ", ")}]
   }'
 changelistentryname = '{name|utf8|json}'
 changeset = '\{