subrepo: (mostly) use relative path in "skipping missing subrepository" This is consistent with the other messages printed by these functions. Note that addremove is a little different and prints absolute (aka repo-relative) paths if no argument was given. Differential Revision: https://phab.mercurial-scm.org/D5900

subrepo: use relative path for "already tracked" message From 932de135041f (subrepo: warn when adding already tracked files in gitsubrepo, 2015-02-27): The file is printed with abs() to be consistent with how it is printed in workingctx, even though that is inconsistent with how added files are printed in verbose mode. However, a few year later, the same author wrote 7008f6819002 (context: name files relative to cwd in warning messages, 2017-07-11) and now it's inconsistent. This fixes that inconsistency. Differential Revision: https://phab.mercurial-scm.org/D5899

diff: make `hg diff --root=subrepo` work The root prefix is currently stripped before adding the subrepo prefix. It seems to me that if you run `hg diff --root=subrepo` and a subrepo/ path is visited (say "subrepo/foo"), then the path generated for the diff would initially be just "foo" and we then fail (if the developer warning is active) to strip the "subrepo/" from the path. It seems like we should first add the prefix in order to produce a path that's relative to the top-level repo, and then we can remove the root prefix from that. There are no tests for this, it seems, and I don't care enough to add one. Differential Revision: https://phab.mercurial-scm.org/D5895

patch: replace "prefix" and "relroot" arguments by "pathfn" (API) The two arguments serve a very similar purpose: "relroot" is stripped from the front of the path, and then "prefix" (a subrepo path) is added (also to the front). Passing in a function that does that is more generic and will make it easier to respect ui.relative-paths in later patches (don't worry, I'm not going to respect that option for regular patches, only for --stat). I'm deliberately not calling it "uipathfn", because it's generally for producing valid diffs (including when prefix is non-empty), so things like using backslash on Windows is not an option. Differential Revision: https://phab.mercurial-scm.org/D5894