builtins + test helpers: use return instead of exit() in cmd_*

Change various cmd_* functions that claim to return an "int" to use
"return" instead of exit() to indicate an exit code. These were not
marked with NORETURN, and by directly exit()-ing we'll skip the
cleanup git.c would otherwise do (e.g. closing fd's, erroring if we
can't). See run_builtin() in git.c.

In the case of shell.c and sh-i18n--envsubst.c this was the result of
an incomplete migration to using a cmd_main() in 3f2e2297b9 (add an
extra level of indirection to main(), 2016-07-01).

This was spotted by SunCC 12.5 on Solaris 10 (gcc210 on the gccfarm).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/t/helper/test-match-trees.c b/t/helper/test-match-trees.c
index b9fd427571..4079fdee06 100644
--- a/t/helper/test-match-trees.c
+++ b/t/helper/test-match-trees.c
@@ -23,5 +23,5 @@ int cmd__match_trees(int ac, const char **av)
 	shift_tree(the_repository, &one->object.oid, &two->object.oid, &shifted, -1);
 	printf("shifted: %s\n", oid_to_hex(&shifted));
 
-	exit(0);
+	return 0;
 }