git-svn: workaround a for broken symlinks in SVN

Eric Wong · Eric Wong · commit 7fc35e0e9478 · 2007-12-19T00:17:07.000-08:00
It's possible for bad clients to commit symlinks without the 5-character "link " prefix in symlinks. So guard around this bug in SVN and make a best effort to create symlinks if the "link " prefix is missing. More information on this SVN bug is described here: http://subversion.tigris.org/issues/show_bug.cgi?id=2692 To be pedantic, there is still a corner case that neither we nor SVN can handle: If somebody made a link using a broken SVN client where "link " is the first part of its path, e.g. "link sausage", then we'd end up having a symlink which points to "sausage" because we incorrectly stripped the "link ". Hopefully this hasn't happened in practice, but if it has, it's not our fault SVN is broken :) Thanks to Benoit Sigoure and Sverre Johansen for reporting and feedback. Signed-off-by: Eric Wong <normalperson@yhbt.net>
diff --git a/git-svn.perl b/git-svn.perl
@@ -3177,9 +3177,15 @@ sub close_file {
 		}
 		sysseek($fh, 0, 0) or croak $!;
 		if ($fb->{mode_b} == 120000) {
-			sysread($fh, my $buf, 5) == 5 or croak $!;
-			$buf eq 'link ' or die "$path has mode 120000",
-			                       "but is not a link\n";
+			eval {
+				sysread($fh, my $buf, 5) == 5 or croak $!;
+				$buf eq 'link ' or die "$path has mode 120000",
+						       " but is not a link";
+			};
+			if ($@) {
+				warn "$@\n";
+				sysseek($fh, 0, 0) or croak $!;
+			}
 		}
 		defined(my $pid = open my $out,'-|') or die "Can't fork: $!\n";
 		if (!$pid) {
