On 22/01/17 22:09, sf...@users.sourceforge.net wrote: > I didn't check the source files of git-fetch, but this symptom indicates > that git-fetch incorrectly tests errno after libau:closedir() returned a > success. > libau can fix this problem (see the attachment again), but it is > definitly better to fix git-fetch.
Right, I see what is happening now. Your patch fixes it, because you now
ensure errno is set to 0 before exiting rdu_lib.c:closedir.
Previously, because no error happening in closedir normally, but 'errno
= EBADF' is ran unconditionally, any use of closedir will result in EBADF.
So, looking at the git code, here is the stack trace of the failure:
=======================================================================
#0 die_errno (fmt=fmt@entry=0x5555556eabe5 "failed to read object %s")
at usage.c:151
#1 0x00005555556829fb in read_sha1_file_extended
(sha1=sha1@entry=0x5555559aa948 "",
type=type@entry=0x7fffffffdbe4, size=size@entry=0x7fffffffdbe8,
flag=flag@entry=1)
at sha1_file.c:2997
#2 0x0000555555641e49 in read_sha1_file (size=0x7fffffffdbe8,
type=0x7fffffffdbe4,
sha1=0x5555559aa948 "") at cache.h:1094
#3 parse_object (sha1=0x5555559aa948 "") at object.c:269
#4 0x00005555555fb402 in lookup_commit_reference_gently
(sha1=<optimized out>, quiet=1)
at commit.c:24
#5 0x000055555558e606 in update_local_ref (ref=0x5555559aa940,
remote=0x5555559a9d0b "experimental",
remote_ref=0x5555559a9c90, display=0x7fffffffdd10, summary_width=17)
at builtin/fetch.c:640
#6 0x000055555558f649 in store_updated_refs (raw_url=<optimized out>,
remote_name=0x5555559a1590 "alioth-git", ref_map=0x5555559a9c90) at
builtin/fetch.c:846
#7 0x000055555558f7ed in fetch_refs (transport=0x5555559a1a90,
ref_map=0x5555559a9c90)
at builtin/fetch.c:907
#8 0x000055555558fa9f in do_fetch (transport=0x5555559a1a90,
refs=0x5555559a0d20, ref_count=0)
at builtin/fetch.c:1119
#9 0x000055555558fd49 in fetch_one (remote=<optimized out>, argc=0,
argv=0x7fffffffe0f8)
at builtin/fetch.c:1293
#10 0x000055555559022b in cmd_fetch (argc=1, argv=0x7fffffffe0f0,
prefix=<optimized out>)
at builtin/fetch.c:1379
#11 0x000055555556549d in run_builtin (p=0x5555559419c0 <commands+768>,
argc=argc@entry=2,
argv=argv@entry=0x7fffffffe0f0) at git.c:373
#12 0x0000555555565623 in handle_builtin (argc=2, argv=0x7fffffffe0f0)
at git.c:572
#13 0x0000555555565b84 in run_argv (argcp=argcp@entry=0x7fffffffdfcc,
argv=argv@entry=0x7fffffffdfc0)
at git.c:630
#14 0x0000555555565ca7 in cmd_main (argc=<optimized out>,
argv=<optimized out>) at git.c:707
#15 0x00005555555e15e2 in main (argc=3, argv=0x7fffffffe0e8) at
common-main.c:40
=======================================================================
sha1_file.c:read_sha1_file_extended is where the errno checking happens,
the function is described as:
=======================================================================
This function dies on corrupt objects; the callers who want to
deal with them should arrange to call read_object() and give error
messages themselves.
=======================================================================
the errno code:
=======================================================================
errno = 0;
data = read_object(repl, type, size);
if (data)
return data;
if (errno && errno != ENOENT)
die_errno("failed to read object %s", sha1_to_hex(sha1));
=======================================================================
In this example, there is no data returned since the remote refs don't
exist locally yet, hence the errno check triggers (and its expecting
'file not found').
Inside read_object at the end calls reprepare_packed_git ->
prepare_packed_git -> prepare_packed_git_one: at the end of this
function, closedir is called.
So, read_sha1_file_extended is trying to summarise any failures that
happen beneath it by checking the errno at that point.
I understand what you are saying from the manpage, however it does seem
reasonable to say that any unusual errno state means a failure has
occurred somewhere (ignoring the fact that released libau currently sets
EBADF even when a failure has not happened).
If I report this to git, I bet they'll just say that libau shouldn't
have set errno without an actual failure to report :/
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