git-svn: find-rev and rebase for SVN::Mirror repositories

find-rev and rebase error out on svm because git-svn doesn't trace the
original svn revision numbers back to git commits. The updated test
case, included in the patch, shows the issue and passes with the rest of
the patch applied.

This fixes Git::SVN::find_by_url to find branches based on the
svm:source URL, where useSvmProps is set. Also makes sure cmd_find_rev
and working_head_info use the information they have to correctly track
the source repository. This is enough to get find-rev and rebase
working.
Signed-off-by: NJoão Abecasis <joao@abecasis.name>
Acked-by: NEric Wong <normalperson@yhbt.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

git-svn.perl

@@ -537,13 +537,13 @@ sub cmd_find_rev {
 		my $head = shift;
 		$head ||= 'HEAD';
 		my @refs;
-		my (undef, undef, undef, $gs) = working_head_info($head, \@refs);
+		my (undef, undef, $uuid, $gs) = working_head_info($head, \@refs);
 		unless ($gs) {
 			die "Unable to determine upstream SVN information from ",
 			    "$head history\n";
 		}
 		my $desired_revision = substr($revision_or_hash, 1);
-		$result = $gs->rev_map_get($desired_revision);
+		$result = $gs->rev_map_get($desired_revision, $uuid);
 	} else {
 		my (undef, $rev, undef) = cmt_metadata($revision_or_hash);
 		$result = $rev;
@@ -1162,7 +1162,7 @@ sub working_head_info {
 		if (defined $url && defined $rev) {
 			next if $max{$url} and $max{$url} < $rev;
 			if (my $gs = Git::SVN->find_by_url($url)) {
-				my $c = $gs->rev_map_get($rev);
+				my $c = $gs->rev_map_get($rev, $uuid);
 				if ($c && $c eq $hash) {
 					close $fh; # break the pipe
 					return ($url, $rev, $uuid, $gs);
@@ -1416,11 +1416,17 @@ sub fetch_all {
 
 sub read_all_remotes {
 	my $r = {};
+	my $use_svm_props = eval { command_oneline(qw/config --bool
+	    svn.useSvmProps/) };
+	$use_svm_props = $use_svm_props eq 'true' if $use_svm_props;
 	foreach (grep { s/^svn-remote\.// } command(qw/config -l/)) {
 		if (m!^(.+)\.fetch=\s*(.*)\s*:\s*refs/remotes/(.+)\s*$!) {
 			my ($remote, $local_ref, $remote_ref) = ($1, $2, $3);
 			$local_ref =~ s{^/}{};
 			$r->{$remote}->{fetch}->{$local_ref} = $remote_ref;
+			$r->{$remote}->{svm} = {} if $use_svm_props;
+		} elsif (m!^(.+)\.usesvmprops=\s*(.*)\s*$!) {
+			$r->{$1}->{svm} = {};
 		} elsif (m!^(.+)\.url=\s*(.*)\s*$!) {
 			$r->{$1}->{url} = $2;
 		} elsif (m!^(.+)\.(branches|tags)=
@@ -1437,6 +1443,23 @@ sub read_all_remotes {
 			}
 		}
 	}
+
+	map {
+		if (defined $r->{$_}->{svm}) {
+			my $svm;
+			eval {
+				my $section = "svn-remote.$_";
+				$svm = {
+					source => tmp_config('--get',
+					    "$section.svm-source"),
+					replace => tmp_config('--get',
+					    "$section.svm-replace"),
+				}
+			};
+			$r->{$_}->{svm} = $svm;
+		}
+	} keys %$r;
+
 	$r;
 }
 
@@ -1563,13 +1586,21 @@ sub find_by_url { # repos_root and, path are optional
 		}
 		my $p = $path;
 		my $rwr = rewrite_root({repo_id => $repo_id});
+		my $svm = $remotes->{$repo_id}->{svm}
+			if defined $remotes->{$repo_id}->{svm};
 		unless (defined $p) {
 			$p = $full_url;
 			my $z = $u;
+			my $prefix = '';
 			if ($rwr) {
 				$z = $rwr;
+			} elsif (defined $svm) {
+				$z = $svm->{source};
+				$prefix = $svm->{replace};
+				$prefix =~ s#^\Q$u\E(?:/|$)##;
+				$prefix =~ s#/$##;
 			}
-			$p =~ s#^\Q$z\E(?:/|$)## or next;
+			$p =~ s#^\Q$z\E(?:/|$)#$prefix# or next;
 		}
 		foreach my $f (keys %$fetch) {
 			next if $f ne $p;

t/t9110-git-svn-use-svm-props.sh

@@ -49,4 +49,13 @@ test_expect_success 'verify metadata for /dir' "
 	   grep '^git-svn-id: $dir_url@1 $uuid$'
 	"
 
+test_expect_success 'find commit based on SVN revision number' "
+        git-svn find-rev r12 |
+	    grep `git rev-parse HEAD`
+        "
+
+test_expect_success 'empty rebase' "
+	git-svn rebase
+	"
+
 test_done