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/builtin/mktree.c b/builtin/mktree.c
index 891991b00d..ae78ca1c02 100644
--- a/builtin/mktree.c
+++ b/builtin/mktree.c
@@ -189,5 +189,5 @@ int cmd_mktree(int ac, const char **av, const char *prefix)
 		used=0; /* reset tree entry buffer for re-use in batch mode */
 	}
 	strbuf_release(&sb);
-	exit(0);
+	return 0;
 }