git-cvsimport: $cvs->file() fails silently

git-cvsimport: $cvs->file() fails silently

[Martin Langhoff]

We have seen a few instances of files extracted from a remote CVS repo
by $cvs->file() being empty, and still git-cvsimport did not die or
complain. If I rewind the affected head and re-run git-cvsimport, the
file is imported correctly, which makes me suspect that the server
went away or there was some other networking glitch, and that the
file() and _file() methods didn't handle it gracefully.

I've been through the file(), _file() and _line() methods, and they
seem pretty conservative -- they die or return undef in all the right
places. There _must_ be one place that we're missing but I just can't
see it.

Any ideas?



martin

Re: git-cvsimport: $cvs->file() fails silently

[Martin Langhoff]

On 10/27/05, Martin Langhoff <martin.langhoff@gmail.com> wrote:
> There _must_ be one place that we're missing but I just can't
> see it.

Got some more info on this. The output of cvsimport when this happens
looks like this:

Read from remote host cvs.sourceforge.net: Connection reset by peer
Read from remote host cvs.sourceforge.net: Connection reset by peer
Update course/enrol.php:  bytes
Use of uninitialized value in split at
/home/martin/local/git/git-cvsimport line 362.
Update lang/en/moodle.php: 66792 bytes
Tree ID ef11ad5a0cf917e98bc477837de1b3f587e12027
Parent ID e972b3a28e1c4802fc5af6a996164c93fb4f3e53
Committed patch 20143 (MOODLE_15_STABLE 2005-10-31 20:31:57)
Commit ID 95a748b0d9cd6dc74e65497561514fa5858c149c

Around line 335  $res = $self->_line($fh); is returning '', which is
defined but otherwise empty. I've patched cvsimport thus to try and
catch this kind of error:

diff --git a/git-cvsimport.perl b/git-cvsimport.perl
index bbb83fb..f594df3 100755
--- a/git-cvsimport.perl
+++ b/git-cvsimport.perl
@@ -337,6 +337,10 @@ sub file {
        }
        close ($fh);

+       if ($res eq '') {
+           die "Looks like the server has gone away during the transaction!";
+       }
+
        return ($name, $res);
 }

@@ -764,6 +768,9 @@ while(<CVS>) {
                my $rev = $3;
                $fn =~ s#^/+##;
                my ($tmpname, $size) = $cvs->file($fn,$rev);
+               if ($size eq '') {
+                       die "Should not happen! Something went wrong
with the remote connection";
+               }
                if($size == -1) {
                        push(@old,$fn);
                        print "Drop $fn\n" if $opt_v;

Now, I'm sure we can catch it in the "right" place, but I'm not sure
where that is.

cheers,


martin