context: avoid using a context object as a changeid I find it misleading to pass changeid=changectx. It currently works to do that because there's weird (IMO) handling of it in basectx.__new__. I'm planning on removing that code. Passing changeid as "changeid" and context as "context" makes it more readable. Note that the documentation of filectx.__init__ doesn't even seem to be aware that a changeid can be a context ("changeset revision, node, or tag"). Differential Revision: https://phab.mercurial-scm.org/D2967

--- a/mercurial/merge.py	Thu Mar 29 21:15:40 2018 -0700
+++ b/mercurial/merge.py	Thu Mar 29 21:29:15 2018 -0700
@@ -561,7 +561,7 @@
         fcd = self._filectxorabsent(hash, wctx, dfile)
         fco = self._filectxorabsent(onode, octx, ofile)
         # TODO: move this to filectxorabsent
-        fca = self._repo.filectx(afile, fileid=anode, changeid=actx)
+        fca = self._repo.filectx(afile, fileid=anode, changectx=actx)
         # "premerge" x flags
         flo = fco.flags()
         fla = fca.flags()