@matheusbsbs / matheus-bagliano / commits / bf68b11699

git: allow alias-shadowing deprecated builtins

git-whatchanged(1) is deprecated and you need to pass `--i-still-use-this` in order to force it to work as before. There are two affected users, or usages: 1. people who use the command in scripts; and 2. people who are used to using it interactively. For (1) the replacement is straightforward.[1] But people in (2) might like the name or be really used to typing it.[3] An obvious first thought is to suggest aliasing `whatchanged` to the git-log(1) equivalent.[1] But this doesn’t work and is awkward since you cannot shadow builtins via aliases. Now you are left in an uncomfortable limbo; your alias won’t work until the command is removed for good. Let’s lift this limitation by allowing *deprecated* builtins to be shadowed by aliases. The only observed demand for aliasing has been for git-whatchanged(1), not for git-pack-redundant(1). But let’s be consistent and treat all deprecated commands the same. [1]: git log --raw --no-merges With a minor caveat: you get different outputs if you happen to have empty commits (no changes)[2] [2]: https://lore.kernel.org/git/20250825085428.GA367101@coredump.intra.peff.net/ [3]: https://lore.kernel.org/git/BL3P221MB0449288C8B0FA448A227FD48833AA@BL3P221MB0449.NAMP221.PROD.OUTLOOK.COM/ Based-on-patch-by: Jeff King <peff@peff.net> Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Kristoffer Haugsbakk committed Sep 17, 2025 at 22:24 UTC bf68b116997a0471dfccf7dcced00eb7d8b66982
3 files changed +59 -1
Documentation/config/alias.adoc
+2 -1
@@ -3,7 +3,8 @@ alias.*::
3 after defining `alias.last = cat-file commit HEAD`, the invocation
4 `git last` is equivalent to `git cat-file commit HEAD`. To avoid
5 confusion and troubles with script usage, aliases that
6 - hide existing Git commands are ignored. Arguments are split by
6 + hide existing Git commands are ignored except for deprecated
7 + commands. Arguments are split by
8 spaces, the usual shell quoting and escaping are supported.
9 A quote pair or a backslash can be used to quote them.
10 +
git.c
+17
@@ -824,12 +824,29 @@ static void execv_dashed_external(const char **argv)
824 exit(128);
825 }
826
827 +static int is_deprecated_command(const char *cmd)
828 +{
829 + struct cmd_struct *builtin = get_builtin(cmd);
830 + return builtin && (builtin->option & DEPRECATED);
831 +}
832 +
833 static int run_argv(struct strvec *args)
834 {
835 int done_alias = 0;
836 struct string_list expanded_aliases = STRING_LIST_INIT_DUP;
837
838 while (1) {
839 + /*
840 + * Allow deprecated commands to be overridden by aliases. This
841 + * creates a seamless path forward for people who want to keep
842 + * using the name after it is gone, but want to skip the
843 + * deprecation complaint in the meantime.
844 + */
845 + if (is_deprecated_command(args->v[0]) &&
846 + handle_alias(args, &expanded_aliases)) {
847 + done_alias = 1;
848 + continue;
849 + }
850 /*
851 * If we tried alias and futzed with our environment,
852 * it no longer is safe to invoke builtins directly in
t/t0014-alias.sh
+40
@@ -27,6 +27,20 @@ test_expect_success 'looping aliases - internal execution' '
27 test_grep "^fatal: alias loop detected: expansion of" output
28 '
29
30 +test_expect_success 'looping aliases - deprecated builtins' '
31 + test_config alias.whatchanged pack-redundant &&
32 + test_config alias.pack-redundant whatchanged &&
33 + cat >expect <<-EOF &&
34 + ${SQ}whatchanged${SQ} is aliased to ${SQ}pack-redundant${SQ}
35 + ${SQ}pack-redundant${SQ} is aliased to ${SQ}whatchanged${SQ}
36 + fatal: alias loop detected: expansion of ${SQ}whatchanged${SQ} does not terminate:
37 + whatchanged <==
38 + pack-redundant ==>
39 + EOF
40 + test_must_fail git whatchanged -h 2>actual &&
41 + test_cmp expect actual
42 +'
43 +
44 # This test is disabled until external loops are fixed, because would block
45 # the test suite for a full minute.
46 #
@@ -55,4 +69,30 @@ test_expect_success 'tracing a shell alias with arguments shows trace of prepare
69 test_cmp expect actual
70 '
71
72 +can_alias_deprecated_builtin () {
73 + cmd="$1" &&
74 + # some git(1) commands will fail for `-h` (the case for
75 + # git-status as of 2025-09-07)
76 + test_might_fail git status -h >expect &&
77 + test_file_not_empty expect &&
78 + test_might_fail git -c alias."$cmd"=status "$cmd" -h >actual &&
79 + test_cmp expect actual
80 +}
81 +
82 +test_expect_success 'can alias-shadow deprecated builtins' '
83 + for cmd in $(git --list-cmds=deprecated)
84 + do
85 + can_alias_deprecated_builtin "$cmd" || return 1
86 + done
87 +'
88 +
89 +test_expect_success 'can alias-shadow via two deprecated builtins' '
90 + # some git(1) commands will fail... (see above)
91 + test_might_fail git status -h >expect &&
92 + test_file_not_empty expect &&
93 + test_might_fail git -c alias.whatchanged=pack-redundant \
94 + -c alias.pack-redundant=status whatchanged -h >actual &&
95 + test_cmp expect actual
96 +'
97 +
98 test_done