Re: git-svn failure when symlink added in svn

From: Junio C Hamano <junkio@cox.net>
Date: Apr 28, 2007, 18:34 UTC
Message-ID: <7v7irwjql6.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <m2odl8fjv1.fsf@ziti.fhcrc.org>

Seth Falcon <sethfalcon@gmail.com> writes:

Show 5 quoted lines

> On OS X, I get:
>
>     ziti:~/temp seth$ ./perltest1.pl 
>     read[5]: link 
>     child says: child: at 5

Ah, so the previous read($fh, $buf, 5) lets stdio absorb the whole (short) input, and the underlying seek pointer is not adjusted back across fork, and the child does not have anything to read.

Show 6 quoted lines

> And uncommenting the sysseek call, I get:
>
>     ziti:~/temp seth$ ./perltest1.pl 
>     read[5]: link 
>     child says: child: at 5
>     child says: >>12345

Then I suspect the following could be less invasive and more efficient fix for the problem. I do not have an access to MacOS box, and I do not have a working sync with any SVN repository, so I cannot test it myself, though...

diff --git a/git-svn.perl b/git-svn.perl
index 7b5f8ab..e487da6 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -2454,6 +2454,7 @@ sub close_file {
 		}
 		defined(my $pid = open my $out,'-|') or die "Can't fork: $!\n";
 		if (!$pid) {
+			sysseek($fh, 5, 0);
 			open STDIN, '<&', $fh or croak $!;
 			exec qw/git-hash-object -w --stdin/ or croak $!;
 		}