shortlog: remove unused(?) "repo-abbrev" feature

Remove support for the magical "repo-abbrev" comment in .mailmap
files. This was added to .mailmap parsing in [1], as a generalized
feature of the git-shortlog Perl script added earlier in [2].

There was no documentation or tests for this feature, and I don't
think it's used in practice anymore.

What it did was to allow you to specify a single string to be
search-replaced with "/.../" in the .mailmap file. E.g. for
linux.git's current .mailmap:

    git archive --remote=git@gitlab.com:linux-kernel/linux.git \
        HEAD -- .mailmap | grep -a repo-abbrev
    # repo-abbrev: /pub/scm/linux/kernel/git/

Then when running e.g.:

    git shortlog --merges --author=Linus -1 v5.10-rc7..v5.10 | grep Merge

We'd emit (the [...] is mine):

      Merge tag [...]git://git.kernel.org/.../tip/tip

But will now emit:

      Merge tag [...]git.kernel.org/pub/scm/linux/kernel/git/tip/tip

I think at this point this is just a historical artifact we can get
rid of. It was initially meant for Linus's own use when we integrated
the Perl script[2], but since then it seems he's stopped using it.

Digging through Linus's release announcements on the LKML[3] the last
release I can find that made use of this output is Linux 2.6.25-rc6
back in March 2008[4]. Later on Linus started using --no-merges[5],
and nowadays seems to prefer some custom not-quite-shortlog format of
merges from lieutenants[6].

You will still see it on linux.git if you run "git shortlog" manually
yourself with --merges, with this removed you can still get the same
output with:

    git log --pretty=fuller v5.10-rc7..v5.10 |
    sed 's!/pub/scm/linux/kernel/git/!/.../!g' |
    git shortlog

Arguably we should do the same for the search-replacing of "[PATCH]"
at the beginning with "". That seems to be another relic of a bygone
era when linux.git patches would have their E-Mail subject lines
applied as-is by "git am" or whatever. But we documented that feature
in "git-shortlog(1)", and it seems more widely applicable than
something purely kernel-specific.

1. 7595e2ee6ef (git-shortlog: make common repository prefix
   configurable with .mailmap, 2006-11-25)
2. fa375c7f1b6 (Add git-shortlog perl script, 2005-06-04)
3. https://lore.kernel.org/lkml/
4. https://lore.kernel.org/lkml/alpine.LFD.1.00.0803161651350.3020@woody.linux-foundation.org/
5. https://lore.kernel.org/lkml/BANLkTinrbh7Xi27an3uY7pDWrNKhJRYmEA@mail.gmail.com/
6. https://lore.kernel.org/lkml/CAHk-=wg1+kf1AVzXA-RQX0zjM6t9J2Kay9xyuNqcFHWV-y5ZYw@mail.gmail.com/

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 14 deletions

diff --git a/builtin/shortlog.c b/builtin/shortlog.c
index c52e4ccd19..e7c21ab620 100644
--- a/builtin/shortlog.c
+++ b/builtin/shortlog.c
@@ -61,8 +61,7 @@ static void insert_one_record(struct shortlog *log,
 	if (log->summary)
 		item->util = (void *)(UTIL_TO_INT(item) + 1);
 	else {
-		const char *dot3 = log->common_repo_prefix;
-		char *buffer, *p;
+		char *buffer;
 		struct strbuf subject = STRBUF_INIT;
 		const char *eol;
 
@@ -82,17 +81,6 @@ static void insert_one_record(struct shortlog *log,
 		format_subject(&subject, oneline, " ");
 		buffer = strbuf_detach(&subject, NULL);
 
-		if (dot3) {
-			int dot3len = strlen(dot3);
-			if (dot3len > 5) {
-				while ((p = strstr(buffer, dot3)) != NULL) {
-					int taillen = strlen(p) - dot3len;
-					memcpy(p, "/.../", 5);
-					memmove(p + 5, p + dot3len, taillen + 1);
-				}
-			}
-		}
-
 		if (item->util == NULL)
 			item->util = xcalloc(1, sizeof(struct string_list));
 		string_list_append(item->util, buffer);
@@ -342,7 +330,7 @@ void shortlog_init(struct shortlog *log)
 {
 	memset(log, 0, sizeof(*log));
 
-	read_mailmap(&log->mailmap, &log->common_repo_prefix);
+	read_mailmap(&log->mailmap);
 
 	log->list.strdup_strings = 1;
 	log->wrap = DEFAULT_WRAPLEN;