Re: GIT_COMMITTER_* and reflog

[Jeff King <peff@peff.net>]

On Sat, Oct 26, 2019 at 04:34:22PM +0900, Junio C Hamano wrote:

> Jonathan Nieder <jrnieder@gmail.com> writes:
> 
> > If GIT_COMMITTER_{NAME,EMAIL} were used when writing reflogs but
> > GIT_COMMITTER_DATE weren't, would that help with your workflow?
> 
> Thanks for a thoughtful response.
> 
> My knee-jerk reaction is that it probably was a design bug that came
> out of laziness that we used the usual mechanism to obtain the
> committer date when deciding the timestamp we leave in reflog
> entries.  Given that we say master@{6.hours.ago} etc., we should
> base the timestamp on something that is coherent with what the end
> users would give us, e.g. "6.hours.ago".  IOW, we should be using
> the wallclock time without paying attention to GIT_COMMITTER_DATE,
> i.e. date.c::get_time().

FWIW, I was about to write a similar response. If people really wanted a
separate reflog ident, I could see introducing $GIT_REFLOG_NAME, etc.
But the current date handling just seems buggy (and an unintended
consequence of reusing the existing ident code).

If somebody wants to pursue a patch, I suspect the solution is probably
something like this (totally untested):

diff --git a/refs/files-backend.c b/refs/files-backend.c
index d60767ab73..2ebf2feeb8 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1658,7 +1658,10 @@ static int files_log_ref_write(struct files_ref_store *refs,
 	if (logfd < 0)
 		return 0;
 	result = log_ref_write_fd(logfd, old_oid, new_oid,
-				  git_committer_info(0), msg);
+				  fmt_ident(getenv("GIT_COMMITTER_NAME"),
+					    getenv("GIT_COMMITTER_EMAIL"),
+					    WANT_COMMITTER_IDENT, NULL, 0),
+				  msg);
 	if (result) {
 		struct strbuf sb = STRBUF_INIT;
 		int save_errno = errno;

-Peff