This segfaults, but should print an error instead, have a repo with a
corrupt HEAD:
(
rm -rf /tmp/git &&
git clone --single-branch --branch todo g...@github.com:git/git.git
/tmp/git &&
echo 1111111111111111111111111111111111111111
>/tmp/git/.git/refs/heads/todo &&
git -C /tmp/git pull
)
On this repository e.g. "git log" will print "fatal: bad object HEAD",
but for some reason "git pull" makes it this far:
$ git pull
Segmentation fault
The immediate reason is that in run_diff_index() we have this:
ent = revs->pending.objects;
And that in this case that's NULL:
(gdb) bt
#0 0x000055555565993f in run_diff_index (revs=0x7fffffffcb90, cached=1) at
diff-lib.c:524
#1 0x00005555557633da in has_uncommitted_changes (ignore_submodules=1) at
wt-status.c:2345
#2 0x00005555557634c9 in require_clean_work_tree (action=0x555555798f18
"pull with rebase", hint=0x555555798efb "please commit or stash them.",
ignore_submodules=1, gently=0) at wt-status.c:2370
#3 0x00005555555dbdee in cmd_pull (argc=0, argv=0x7fffffffd868,
prefix=0x0) at builtin/pull.c:885
#4 0x000055555556c9da in run_builtin (p=0x555555a2de50 <commands+1872>,
argc=1, argv=0x7fffffffd868) at git.c:417
#5 0x000055555556cce2 in handle_builtin (argc=1, argv=0x7fffffffd868) at
git.c:633
#6 0x000055555556ce8a in run_argv (argcp=0x7fffffffd71c,
argv=0x7fffffffd710) at git.c:685
#7 0x000055555556d03f in cmd_main (argc=1, argv=0x7fffffffd868) at
git.c:762
#8 0x0000555555611786 in main (argc=3, argv=0x7fffffffd858) at
common-main.c:45
(gdb) p revs
$4 = (struct rev_info *) 0x7fffffffcb90
(gdb) p revs->pending
$5 = {nr = 0, alloc = 0, objects = 0x0}
(gdb)
This has been an issue since at least v2.8.0 (didn't test back
further). I'm not familiar with the status / diff code, so I'm not sure
where the assertion should be added.
This came up in the wild due to a user with a corrupt repo (don't know
how it got corrupt) trying "git pull" and seeing git segfault.
