Re: [RFC] Build in clone

[Johan Herland <johan@herland.net>]

On Tuesday 26 February 2008, Johan Herland wrote:
> Running this test with GDB, I get the following backtrace:
> 
> #0  0x0000000000474b87 in is_null_sha1 (sha1=0x100000008 <Address 0x100000008 out of bounds>) at cache.h:464
> #1  0x0000000000474ad3 in do_one_ref (base=0x4dc8ff "refs/", fn=0x419471 <setup_tmp_ref>, trim=0, cb_data=0x7498d0, entry=0xffffffff) at refs.c:474
> #2  0x0000000000474e28 in do_for_each_ref (base=0x4dc8ff "refs/", fn=0x419471 <setup_tmp_ref>, trim=0, cb_data=0x7498d0) at refs.c:558
> #3  0x0000000000474ecd in for_each_ref (fn=0x419471 <setup_tmp_ref>, cb_data=0x7498d0) at refs.c:580
> #4  0x0000000000419706 in setup_reference (repo=0x745070 "C/.git") at builtin-clone.c:211
> #5  0x0000000000419fce in cmd_clone (argc=2, argv=0x7fff7a282fa0, prefix=0x0) at builtin-clone.c:422
> #6  0x0000000000404ba3 in run_command (p=0x6ff710, argc=7, argv=0x7fff7a282fa0) at git.c:248
> #7  0x0000000000404d55 in handle_internal_command (argc=7, argv=0x7fff7a282fa0) at git.c:378
> #8  0x0000000000404ebe in main (argc=7, argv=0x7fff7a282fa0) at git.c:442
> 
> Seems the "loose" ref_list in do_for_each_ref() becomes corrupted.

...and the corruption is done when setup_tmp_ref() calls write_ref_sha1()
which calls invalidate_cached_refs() (which frees the ref_list that
do_for_each_ref() is iterating over).

Not sure how to best solve this. Maybe setup_tmp_ref() shouldn't use
write_ref_sha1(), but write the ref file directly instead, as hinted
at in a comment in setup_tmp_ref()?


...Johan

-- 
Johan Herland, <johan@herland.net>
www.herland.net