obshistory: remove obsfateverb/obsfateprinter patching compatibility obsutil.obsfateverb() was introduced in 3d0f8918351b (hg 4.4) and renamed in b81ad5b78a81 (hg 4.5). Considering the supported evolve versions, the first check is unnecessary (the condition is always True) obsutil.obsfateprinter() was introduced in e27f1f04c2cf (hg 4.4).

obshistory: drop unused keyword argument to _getobsfateandsuccs()

obshistory: use successorsandmarkers() from obsutil, drop local variant It's been in core since 4.4 and is identical to the version removed by this patch, except it returns None if ctx is not obsolete.