git-svn: correctly handle revision 0 in SVN repositories

some SVN repositories have a revision 0 (committed by no author
and no date) when created; so when we need to ensure that we
check any revision variables are defined, and not just
non-zero.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/git-svn.perl b/git-svn.perl
index f0db4af58c69f6f542552651dcde02be02905f3b..6feae56c0eb9856f018da33a4a1461be7c01373d 100755 (executable)
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -232,7 +232,7 @@ sub rebuild {
                my @commit = grep(/^git-svn-id: /,`git-cat-file commit $c`);
                next if (!@commit); # skip merges
                my ($url, $rev, $uuid) = extract_metadata($commit[$#commit]);
-               if (!$rev || !$uuid) {
+               if (!defined $rev || !$uuid) {
                        croak "Unable to extract revision or UUID from ",
                                "$c, $commit[$#commit]\n";
                }
@@ -832,8 +832,14 @@ sub commit_diff {
                print STDERR "Needed URL or usable git-svn id command-line\n";
                commit_diff_usage();
        }
-       my $r = shift || $_revision;
-       die "-r|--revision is a required argument\n" unless (defined $r);
+       my $r = shift;
+       unless (defined $r) {
+               if (defined $_revision) {
+                       $r = $_revision
+               } else {
+                       die "-r|--revision is a required argument\n";
+               }
+       }
        if (defined $_message && defined $_file) {
                print STDERR "Both --message/-m and --file/-F specified ",
                                "for the commit message.\n",
@@ -2493,7 +2499,7 @@ sub extract_metadata {
        my $id = shift or return (undef, undef, undef);
        my ($url, $rev, $uuid) = ($id =~ /^git-svn-id:\s(\S+?)\@(\d+)
                                                        \s([a-f\d\-]+)$/x);
-       if (!$rev || !$uuid || !$url) {
+       if (!defined $rev || !$uuid || !$url) {
                # some of the original repositories I made had
                # identifiers like this:
                ($rev, $uuid) = ($id =~/^git-svn-id:\s(\d+)\@([a-f\d\-]+)/);