Re: gitweb on kernel.org broken

From: Junio C Hamano <junkio@cox.net>
Date: Jan 16, 2006, 20:02 UTC
Message-ID: <7vwth0rlfm.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <20060116190556.GA14184@vrfy.org>

Kay Sievers <kay.sievers@vrfy.org> writes:

>> Junio, seems your "textual symref HEAD" change is causing this?

Yeah, I assumed git_read_head() is called only on a repository that was verified to be valid, and the subroutine did not check the case where HEAD does not verify. My bad. The attached patch should solve this.

The error log says hotplug-ng.git is triggering it. I wonder what is so special about that repository. I hope it is transient during mirroring that mirrored HEAD before objects, not a corrupt repository at the mirroring source.

	... goes to kernel.org mirroring source machine ...

Ugh. It is _not_ a valid git repository. HEAD should be either a symlink or a symref pointing somewhere under refs/heads/, but in that directory, it instead is a regular file that contains an object name. There is nothing under refs/ either:

        $ ls -l /pub/scm/linux/hotplug/hotplug-ng.git/HEAD
        -rw-r--r--  2 gregkh users 41 May  6  2005 /pub/s...ug-ng.git/HEAD
	$ cat /pub/scm/linux/hotplug/hotplug-ng.git/HEAD
        b26bec9f620a969fe5238e8666ab698f197df488
	$ ls -l /pub/scm/linux/hotplug/hotplug-ng.git/refs
	total 0
	$ exit

Greg, could you let me know what is going on with this repository, please?

First of all, I am wondering if this repository is still used (maintained); a regular file HEAD that contains an object name would have stopped working on Aug 27 2005 with this commit at the latest, maybe even before that:

    diff-tree 5f5608b... (from 9740d28...
    Author: Linus Torvalds <torvalds@osdl.org>
    Date:   Sat Aug 27 13:54:42 2005 -0700

    [PATCH] Make .git directory validation code test HEAD

    Inspired by a report by Kalle Valo, this changes git-sh-setup-script and
    the "setup_git_directory()" function to test that $GIT_DIR/HEAD is a
    symlink, since a number of core git features depend on that these days.
    ...

The way I expected to see that part of the directory laid out in a valid git repository would be:

	$ cd /pub/scm/linux/hotplug/hotplug-ng.git/
	$ mkdir -p refs/heads
	$ cat HEAD >refs/heads/master
	$ rm -f HEAD
	$ ln -s refs/heads/master HEAD

Anyhow, here is a gitweb patch to skip this.

---

diff --git a/gitweb.cgi b/gitweb.cgi
index 986d7da..f3853e7 100755
--- a/gitweb.cgi
+++ b/gitweb.cgi
@@ -404,9 +404,8 @@ sub git_read_head {
 	if (open my $fd, "-|", "$gitbin/git-rev-parse", "--verify", "HEAD") {
 		my $head = <$fd>;
 		close $fd;
-		chomp $head;
-		if ($head =~ m/^[0-9a-fA-F]{40}$/) {
-			$retval = $head;
+		if (defined $head && $head =~ /^([0-9a-fA-F]{40})$/) {
+			$retval = $1;
 		}
 	}
 	$ENV{'GIT_DIR'} = $oENV;