tests: add test for hg-test-mode emacs code This is just coverage for the compilation-mode support, but that was enough of a hassle that I wanted to have it covered somehow. Test methodology is _extremely_ cargo-culted from the test for compilation-mode in emacs, so I still have no idea what I'm doing. Differential Revision: https://phab.mercurial-scm.org/D6003

hghave: add check for GNU emacs Differential Revision: https://phab.mercurial-scm.org/D6002

contrib: also linkify tracebacks in compilation output when using hg-test-mode Differential Revision: https://phab.mercurial-scm.org/D6001

contrib: add compilation-mode linking for our test output These regular expressions will cause compilation-mode buffers in emacs to link to source when there are check-code errors in the output of a .t test. In the true tradition of this file, I also have no idea what I'm doing. Differential Revision: https://phab.mercurial-scm.org/D6000

diff: make sure we output stat even when --git is not passed (issue4037) (BC) Before this patch, `hg diff --stat` will give an empty output. It will not show the stat information. I debugged and found that the underlying code does not return the diff header and due to that, other code paths fails to parse that as a diff. I looked into why we don't return diff headers in quiet mode and found the behavior is from 8f8bb77d560e70bcc95577e4dfa877df18d876ab which does not have any mention about why it is done. We also show the diff headers in git, so I think it's fine showing diff header in normal diff in quiet mode. Differential Revision: https://phab.mercurial-scm.org/D6007

tests: add test to demonstrate issue4037 `hg diff --stat -q --config diff.git=0` does not output anything whereas it should print the stat. This is a quiet old bug dating to 2013 and looking at code I think it exists it since 2005 or when --stat was introduced. The next patch will fix the bug. Differential Revision: https://phab.mercurial-scm.org/D6006

grep: reuse getrenamedfn() from scmutil My motivation is to reduce uses of filectx.renamed(). Reusing scmutil.getrenamedfn() also means that we get some caching of copy information per file and revision. I don't think that matters for `hg grep` (I doubt it speeds up significantly, and I doubt it wastes significant memory), but I'm not sure. Differential Revision: https://phab.mercurial-scm.org/D6022

templatekw: move getrenamedfn() to scmutil (API) The function is already used by `hg log` (for following renames, not for templates), so it seems it does not belong in templatekw. Differential Revision: https://phab.mercurial-scm.org/D6021

mq: get copy source from context object instead of from filelog This removes dependence on filelog.renamed(). Differential Revision: https://phab.mercurial-scm.org/D6020

mq: slightly modernize by using context object Context objects have existed since mid-2006. Differential Revision: https://phab.mercurial-scm.org/D6019

absorb: migrate to new method for getting copy info Differential Revision: https://phab.mercurial-scm.org/D6018

fix: migrate to new method for getting copy info Differential Revision: https://phab.mercurial-scm.org/D6017

memfilefromctx: migrate to new method for getting copy info Differential Revision: https://phab.mercurial-scm.org/D6016

largefiles: migrate to new method for getting copy info Differential Revision: https://phab.mercurial-scm.org/D6015

commit: migrate to new method for getting copy info Differential Revision: https://phab.mercurial-scm.org/D6014

tests: migrate to new method for getting copy info Differential Revision: https://phab.mercurial-scm.org/D6013