From bd4ca09d4cddc226ece1bb5b40a74ba281f3e00e Mon Sep 17 00:00:00 2001 From: Thomas Rast Date: Thu, 4 Apr 2013 22:41:41 +0200 Subject: [PATCH] perl: redirect stderr to /dev/null instead of closing On my system, t9100.1 triggers the following warning: ==352== Syscall param write(buf) points to uninitialised byte(s) ==352== at 0x57119C0: __write_nocancel (in /lib64/libc-2.17.so) ==352== by 0x56AC1D2: _IO_file_write@@GLIBC_2.2.5 (in /lib64/libc-2.17.so) ==352== by 0x56AC0B1: new_do_write (in /lib64/libc-2.17.so) ==352== by 0x56AD3B4: _IO_do_write@@GLIBC_2.2.5 (in /lib64/libc-2.17.so) ==352== by 0x56AD6FE: _IO_file_overflow@@GLIBC_2.2.5 (in /lib64/libc-2.17.so) ==352== by 0x56AE3D8: _IO_default_xsputn (in /lib64/libc-2.17.so) ==352== by 0x56ACAA2: _IO_file_xsputn@@GLIBC_2.2.5 (in /lib64/libc-2.17.so) ==352== by 0x5682133: buffered_vfprintf (in /lib64/libc-2.17.so) ==352== by 0x567CE9D: vfprintf (in /lib64/libc-2.17.so) ==352== by 0x5687096: fprintf (in /lib64/libc-2.17.so) ==352== by 0x4E7AC5: vreportf (usage.c:15) ==352== by 0x4E7B14: die_builtin (usage.c:38) The actual complaint appears to be a bug in the underlying implementation. What's interesting here is that it is apparently _triggered_ by closing stderr, which results in (from strace) write(2, "fatal: Needed a single revision\n", 32) = -1 EBADF (Bad file descriptor) write(2, "\0", 1) = -1 EBADF (Bad file descriptor) Closing stderr is a bad idea anyway: there is a very real chance that we print fatal error messages to some other file that just happens to be opened on the now-free FD 2. So let's not do that. As pointed out by Eric Wong (thanks), the initial close needs to go: die() would again write nowhere if we close STDERR beforehand. Signed-off-by: Thomas Rast Signed-off-by: Eric Wong Signed-off-by: Junio C Hamano --- perl/Git.pm | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/perl/Git.pm b/perl/Git.pm index 57a17160f9..4778428830 100644 --- a/perl/Git.pm +++ b/perl/Git.pm @@ -1335,12 +1335,12 @@ sub _command_common_pipe { if (not defined $pid) { throw Error::Simple("open failed: $!"); } elsif ($pid == 0) { - if (defined $opts{STDERR}) { - close STDERR; - } if ($opts{STDERR}) { open (STDERR, '>&', $opts{STDERR}) or die "dup failed: $!"; + } elsif (defined $opts{STDERR}) { + open (STDERR, '>', '/dev/null') + or die "opening /dev/null failed: $!"; } _cmd_exec($self, $cmd, @args); } -- 2.11.4.GIT