mq: prefer a loop to a double-for list comprehension The [x for y in l for x in y] syntax is nigh-incomprehensible, and this is a particularly easy case to expand into a loop since there's no 'if' condition in the list comprehension.

graphlog: mark as deprecated

tests: don't load unnecessary graphlog extension Since graphlog is in core, we can use 'hg log -G' instead.

hg: remove outdated comment The graphlog functionality has been in core since Mercurial 2.3.