# git for-each-ref crashes for %(body) with tags 3 messages from 2008-08-20 to 2008-08-20. Participants: Han-Wen Nienhuys, Junio C Hamano. Thread: https://gitlist.dev/t/15112 ## Han-Wen Nienhuys, 2008-08-20 18:28 Subject: git for-each-ref crashes for %(body) with tags Message-ID: URL: https://gitlist.dev/e/f329bf540808201128r2d21c40cr37eb63a6706ac0aa%40mail.gmail.com ``` Hi, see gdb trace below. Unfortunately, I don't have a repo that I can readily share to demonstrate this. (gdb) r for-each-ref --format '%(body)' refs/tags .. Breakpoint 1, grab_sub_body_contents (val=, deref=0, obj=, buf=0x8146ad0, sz=161) at builtin-for-each-ref.c:494 494 v->s = xstrdup(bodypos); (gdb) p bodypos $10 = 0x0 (gdb) n 496 v->s = xstrdup(subpos); (gdb) n Program received signal SIGSEGV, Segmentation fault. 0x4d9ff013 in strlen () from /lib/tls/i686/cmov/libc.so.6 -- Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen ``` ## Junio C Hamano, 2008-08-20 19:12 Subject: Re: git for-each-ref crashes for %(body) with tags Message-ID: <7vhc9fqz4a.fsf@gitster.siamese.dyndns.org> URL: https://gitlist.dev/e/7vhc9fqz4a.fsf%40gitster.siamese.dyndns.org In-Reply-To: ``` "Han-Wen Nienhuys" writes: > see gdb trace below. Unfortunately, I don't have a repo that I can > readily share to demonstrate this. You have a tag that has a single incomplete line as its payload. The attached patch should fix it, but I wonder how you created such an unusual (I would not say "broken") tag to begin with? diff --git i/builtin-for-each-ref.c w/builtin-for-each-ref.c index 445039e..4d25ec5 100644 --- i/builtin-for-each-ref.c +++ w/builtin-for-each-ref.c @@ -459,8 +459,10 @@ static void find_subpos(const char *buf, unsigned long sz, const char **sub, con return; *sub = buf; /* first non-empty line */ buf = strchr(buf, '\n'); - if (!buf) + if (!buf) { + *body = ""; return; /* no body */ + } while (*buf == '\n') buf++; /* skip blank between subject and body */ *body = buf; ``` ## Han-Wen Nienhuys, 2008-08-20 20:41 Subject: Re: git for-each-ref crashes for %(body) with tags Message-ID: URL: https://gitlist.dev/e/f329bf540808201341m183da990hef93d35c08773b86%40mail.gmail.com In-Reply-To: <7vhc9fqz4a.fsf@gitster.siamese.dyndns.org> ``` >From what I can see, the command responsible was git tag empty it still works (v1.6.0): $ git tag this-tag-has-no-body $ git cat-file tag this-tag-has-no-body fatal: git-cat-file this-tag-has-no-body: bad file $ git cat-file commit this-tag-has-no-body |head -2 tree b51a1eb73af67d17f12114ed3e1e6f93d5adbaa8 parent 49e532412bbc84e4fb73f0862df61882dd7dbf89 On Wed, Aug 20, 2008 at 4:12 PM, Junio C Hamano wrote: > "Han-Wen Nienhuys" writes: > >> see gdb trace below. Unfortunately, I don't have a repo that I can >> readily share to demonstrate this. > > You have a tag that has a single incomplete line as its payload. The > attached patch should fix it, but I wonder how you created such an unusual > (I would not say "broken") tag to begin with? > > > diff --git i/builtin-for-each-ref.c w/builtin-for-each-ref.c > index 445039e..4d25ec5 100644 > --- i/builtin-for-each-ref.c > +++ w/builtin-for-each-ref.c > @@ -459,8 +459,10 @@ static void find_subpos(const char *buf, unsigned long sz, const char **sub, con > return; > *sub = buf; /* first non-empty line */ > buf = strchr(buf, '\n'); > - if (!buf) > + if (!buf) { > + *body = ""; > return; /* no body */ > + } > while (*buf == '\n') > buf++; /* skip blank between subject and body */ > *body = buf; > -- Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen ```