From: Junio C Hamano <gitster@pobox.com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Cc: git@vger.kernel.org, "Todd Zullinger" <tmz@pobox.com>,
"Petr Šplíchal" <psplicha@redhat.com>
Subject: Re: [PATCH] checkout: fix BUG() case in 9081a421a6
Date: Fri, 21 Jan 2022 16:33:47 -0800 [thread overview]
Message-ID: <xmqqr190d2xg.fsf@gitster.g> (raw)
In-Reply-To: <patch-1.1-21ddf7c628d-20220120T212233Z-avarab@gmail.com> ("Ævar Arnfjörð Bjarmason"'s message of "Thu, 20 Jan 2022 22:26:57 +0100")
Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:
> diff --git a/builtin/checkout.c b/builtin/checkout.c
> index 6a5dd2a2a22..52a47ef40e1 100644
> --- a/builtin/checkout.c
> +++ b/builtin/checkout.c
> @@ -1090,13 +1090,10 @@ static int switch_branches(const struct checkout_opts *opts,
> FREE_AND_NULL(old_branch_info.path);
>
> if (old_branch_info.path) {
> - const char *const prefix = "refs/heads/";
> - const char *p;
> - if (skip_prefix(old_branch_info.path, prefix, &p))
> - old_branch_info.name = xstrdup(p);
> - else
> - BUG("should be able to skip past '%s' in '%s'!",
> - prefix, old_branch_info.path);
> + const char *p = old_branch_info.path;
> +
> + skip_prefix(old_branch_info.path, "refs/heads/", &p);
> + old_branch_info.name = xstrdup(p);
> }
What we want is a faithful reversion wrt the behaviour, while
keeping the leakfix.
The old code did
skip_prefix(old_branch_info.path, "refs/heads", &old_branch_info.name);
meaning that old_branch_info.name is left unchanged if .path did not
begin with "refs/heads".
The function that uses old_branch_info.name prepared at this point
in the flow is merge_working_tree(), where it uses .name for the
textual label for the "ancestor" tree. It is preferrable to have a
branch name, but the code is prepared to see NULL in there, where it
comes up with an abbreviated commit object name.
o.ancestor = old_branch_info->name;
if (old_branch_info->name == NULL) {
strbuf_add_unique_abbrev(&old_commit_shortname,
&old_branch_info->commit->object.oid,
DEFAULT_ABBREV);
o.ancestor = old_commit_shortname.buf;
}
As 9081a421a6 properly 0-initializes old_branch_info, I think it is
sufficient to just drop the "else BUG" clause; we shouldn't have to
copy the .path that does not begin with "refs/heads/" there; .name
member would be NULL in such a case.
I do not care too much about reverting the constant that is only
used once into a literal. So, how about doing it this way instead?
builtin/checkout.c | 3 ---
1 file changed, 3 deletions(-)
diff --git i/builtin/checkout.c w/builtin/checkout.c
index 43d0275187..1fb34d537d 100644
--- i/builtin/checkout.c
+++ w/builtin/checkout.c
@@ -1094,9 +1094,6 @@ static int switch_branches(const struct checkout_opts *opts,
const char *p;
if (skip_prefix(old_branch_info.path, prefix, &p))
old_branch_info.name = xstrdup(p);
- else
- BUG("should be able to skip past '%s' in '%s'!",
- prefix, old_branch_info.path);
}
if (opts->new_orphan_branch && opts->orphan_from_empty_tree) {
next prev parent reply other threads:[~2022-01-22 0:33 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-20 16:51 [BUG] builtin/checkout.c:1098: should be able to skip past 'refs/heads/' Todd Zullinger
2022-01-20 17:04 ` Todd Zullinger
2022-01-20 21:26 ` [PATCH] checkout: fix BUG() case in 9081a421a6 Ævar Arnfjörð Bjarmason
2022-01-20 22:29 ` Junio C Hamano
2022-01-20 22:33 ` Junio C Hamano
2022-01-21 11:14 ` Ævar Arnfjörð Bjarmason
2022-01-21 14:29 ` Petr Šplíchal
2022-01-21 21:58 ` Todd Zullinger
2022-01-21 21:19 ` Junio C Hamano
2022-01-20 22:33 ` Todd Zullinger
2022-01-22 0:33 ` Junio C Hamano [this message]
2022-01-22 0:45 ` Junio C Hamano
2022-01-22 0:58 ` [PATCH] checkout: avoid BUG() when hitting a broken repository Junio C Hamano
2022-01-22 8:10 ` Johannes Sixt
2022-01-22 11:55 ` Ævar Arnfjörð Bjarmason
2022-01-23 16:38 ` Johannes Schindelin
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