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Suspicious fetch-pack behaviour




Hi,

One of my users reported a strange problem: a simple HTTPS clone did
not work with Git 1.8.3.1 on RedHat 7.
I did many tests and I was not able to understand why his clone don't
work while I'm able to do it on other similar host.

Nevertheless, we did more investigations. One of them: a raw strace.
I discovered two strange behaviours:
- fetch-pack closes its standard input and standard output and then
tries to print the references on standard input and finaly dies.
- git-remote-https does not react to fetch-pack death and continue
polling an empty set of FD.

Reading fetch-pack code, the behaviour is explicit:
When "--stateless-rpc" is provided, fd is filled with standard input
and standard ouput which are then closed.
https://git.kernel.org/pub/scm/git/git.git/tree/builtin/fetch-pack.c?h=v1.8.3.1#n156

Reading this, I did not understand why it could work.
Any help appreciated.

Here is the strace's extract:

2801  getdents(3, /* 2 entries */, 32768) = 48
2801  getdents(3, /* 0 entries */, 32768) = 0
2801  close(3)                          = 0
2801  close(0)                          = 0
2801  close(1)                          = 0
2801  fstat(1, 0x7ffe10ab4730)          = -1 EBADF (Bad file descriptor)
2801  mmap(NULL, 8192, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f220c9e3000
2801  fstat(1, 0x7ffe10ab5040)          = -1 EBADF (Bad file descriptor)
2801  write(1, "4df1dbf3224064cc5dd2e4c095da2dda"..., 159) = -1 EBADF
(Bad file descriptor)
2801  exit_group(0)                     = ?
2801  +++ exited with 0 +++
2769  <... poll resumed> )              = ? ERESTART_RESTARTBLOCK
(Interrupted by signal)
2769  --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=2801,
si_uid=7561, si_status=0, si_utime=0, si_stime=0} ---
2769  restart_syscall(<... resuming interrupted poll ...>) = 0
2769  poll(NULL, 0, 1000)               = 0 (Timeout)
2769  poll(NULL, 0, 1000)               = 0 (Timeout)
2769  poll(NULL, 0, 1000)               = 0 (Timeout)
2769  poll(NULL, 0, 1000)               = 0 (Timeout)
2769  poll(NULL, 0, 1000)               = 0 (Timeout)
2769  poll(NULL, 0, 1000)               = 0 (Timeout)

-- 
Guilhem BONNEFILLE
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