git-svn: add support for SVN::Mirror/svk using revprops for metadata

Pass --use-svm-props or set the svn.usesvmprops key with git-config
to enable using properties set by SVN::Mirror when it mirrored the
upstream URL.

This is heavily based on work from Sam Vilain:
> From: Sam Vilain <sam@vilain.net>
> Date: Sun, 11 Feb 2007 12:34:45 +1300
> Subject: [PATCH] git-svn: re-map repository URLs and UUIDs on SVK mirror paths
>
> If an SVN revision has a property, "svm:headrev", it is likely that
> the revision was created by SVN::Mirror (a part of SVK).  The property
> contains a repository UUID and a revision.  We want to make it look
> like we are mirroring the original URL, so introduce a helper function
> that returns the original identity URL and UUID, and use it when
> generating commit messages.

Signed-off-by: Eric Wong <normalperson@yhbt.net>

diff --git a/git-svn.perl b/git-svn.perl
index 7e1a6552596fcfbb3833e1fb64b782a660ae9b85..23e1d42cf74d8994cfbd6083be3a033bec3497be 100755 (executable)
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -64,6 +64,7 @@ my %fc_opts = ( 'follow-parent|follow!' => \$Git::SVN::_follow_parent,
                'authors-file|A=s' => \$_authors,
                'repack:i' => \$Git::SVN::_repack,
                'no-metadata' => \$Git::SVN::_no_metadata,
+               'use-svm-props|svm-props' => \$Git::SVN::_use_svm_props,
                'quiet|q' => \$_q,
                'repack-flags|repack-args|repack-opts=s' =>
                   \$Git::SVN::_repack_flags,
@@ -645,7 +646,7 @@ package Git::SVN;
 use strict;
 use warnings;
 use vars qw/$default_repo_id $default_ref_id $_no_metadata $_follow_parent
-            $_repack $_repack_flags/;
+            $_repack $_repack_flags $_use_svm_props/;
 use Carp qw/croak/;
 use File::Path qw/mkpath/;
 use File::Copy qw/copy/;
@@ -920,9 +921,54 @@ sub new {
 
 sub refname { "refs/remotes/$_[0]->{ref_id}" }
 
+sub set_svm_vars {
+       my ($self, $ra) = @_;
+       my $section = "svn-remote.$self->{repo_id}";
+
+       # see if we have it in our config, first:
+       eval {
+               $self->{svm} = {
+                 source => $self->tmp_config('--get', "$section.svm-source"),
+                 uuid => $self->tmp_config('--get', "$section.svm-uuid"),
+               }
+       };
+       return $ra if ($self->{svm}->{source} && $self->{svm}->{uuid});
+
+       # nope, make sure we're connected to the repository root:
+       if ($ra->{repos_root} ne $self->{url}) {
+               $ra = Git::SVN::Ra->new($ra->{repos_root});
+       }
+       my $r = $ra->get_latest_revnum;
+       my ($props) = ($ra->get_dir('', $r))[2];
+       if (my $src = $props->{'svm:source'}) {
+               # don't know what a '!' is there for, also the
+               # username is of no interest
+               $src =~ s{!$}{};
+               $src =~ s{(^[a-z\+]*://)[^/@]*@}{$1};
+               $self->tmp_config('--add', "$section.svm-source", $src);
+
+               my $uuid = $props->{'svm:uuid'};
+               $uuid =~ m{^[0-9a-f\-]{30,}$}
+                   or die "doesn't look right - svm:uuid is '$uuid'\n";
+               $self->tmp_config('--add', "$section.svm-uuid", $uuid);
+
+               $self->{svm} = { source => $src , uuid => $uuid };
+       }
+       if ($ra->{repos_root} ne $self->{url}) {
+               $ra = Git::SVN::Ra->new($self->{url});
+       }
+       $ra;
+}
+
 sub ra {
        my ($self) = shift;
-       Git::SVN::Ra->new($self->{url});
+       my $ra = Git::SVN::Ra->new($self->{url});
+       $self->{-use_svm_props} = $Git::SVN::_use_svm_props;
+       if ($self->{-use_svm_props} && !$self->{svm}) {
+               $ra = $self->set_svm_vars($ra);
+               $self->{-want_revprops} = 1;
+       }
+       $ra;
 }
 
 sub rel_path {
@@ -1006,16 +1052,44 @@ sub get_fetch_range {
        (++$min, $max);
 }
 
+sub tmp_config {
+       my ($self, @args) = @_;
+       unless (-f $self->{config}) {
+               open my $fh, '>', $self->{config} or
+                   die "Can't open $self->{config}: $!\n";
+               print $fh "; This file is used internally by git-svn\n" or
+                     die "Couldn't write to $self->{config}: $!\n";
+               print $fh "; You should not have to edit it\n" or
+                     die "Couldn't write to $self->{config}: $!\n";
+               close $fh or die "Couldn't close $self->{config}: $!\n";
+       }
+       my $old_config = $ENV{GIT_CONFIG};
+       $ENV{GIT_CONFIG} = $self->{config};
+       $@ = undef;
+       my @ret = eval { command('config', @args) };
+       my $err = $@;
+       if (defined $old_config) {
+               $ENV{GIT_CONFIG} = $old_config;
+       } else {
+               delete $ENV{GIT_CONFIG};
+       }
+       die $err if $err;
+       wantarray ? @ret : $ret[0];
+}
+
 sub tmp_index_do {
        my ($self, $sub) = @_;
        my $old_index = $ENV{GIT_INDEX_FILE};
        $ENV{GIT_INDEX_FILE} = $self->{index};
-       my @ret = &$sub;
-       if ($old_index) {
+       $@ = undef;
+       my @ret = eval { &$sub };
+       my $err = $@;
+       if (defined $old_index) {
                $ENV{GIT_INDEX_FILE} = $old_index;
        } else {
                delete $ENV{GIT_INDEX_FILE};
        }
+       die $err if $err;
        wantarray ? @ret : $ret[0];
 }
 
@@ -1105,9 +1179,8 @@ sub do_git_commit {
                                                                   or croak $!;
        print $msg_fh $log_entry->{log} or croak $!;
        unless ($_no_metadata) {
-               print $msg_fh "\ngit-svn-id: ", $self->full_url, '@',
-                             $log_entry->{revision}, ' ',
-                             $self->ra->uuid, "\n" or croak $!;
+               print $msg_fh "\ngit-svn-id: $log_entry->{metadata}\n"
+                             or croak $!;
        }
        $msg_fh->flush == 0 or croak $!;
        close $msg_fh or croak $!;
@@ -1123,7 +1196,11 @@ sub do_git_commit {
 
        $self->{last_rev} = $log_entry->{revision};
        $self->{last_commit} = $commit;
-       print "r$log_entry->{revision} = $commit ($self->{ref_id})\n";
+       print "r$log_entry->{revision}";
+       if (defined $log_entry->{svm_revision}) {
+                print " (\@$log_entry->{svm_revision})";
+       }
+       print " = $commit ($self->{ref_id})\n";
        if (defined $_repack && (--$_repack_nr == 0)) {
                $_repack_nr = $_repack;
                # repack doesn't use any arguments with spaces in them, does it?
@@ -1351,13 +1428,16 @@ sub make_log_entry {
        my %log_entry = ( parents => $parents || [], revision => $rev,
                          log => '');
 
+       my $headrev;
        my $logged = delete $self->{logged_rev_props};
-       if (!$logged || $self->{-want_extra_revprops}) {
+       if (!$logged || $self->{-want_revprops}) {
                my $rp = $self->ra->rev_proplist($rev);
                foreach (sort keys %$rp) {
                        my $v = $rp->{$_};
                        if (/^svn:(author|date|log)$/) {
                                $log_entry{$1} = $v;
+                       } elsif ($_ eq 'svm:headrev') {
+                               $headrev = $v;
                        } else {
                                print $un "  rev_prop: ", uri_encode($_), ' ',
                                          uri_encode($v), "\n";
@@ -1371,6 +1451,21 @@ sub make_log_entry {
        $log_entry{date} = parse_svn_date($log_entry{date});
        $log_entry{author} = check_author($log_entry{author});
        $log_entry{log} .= "\n";
+       if (defined $headrev && $self->{-use_svm_props}) {
+               my ($uuid, $r) = $headrev =~ m{^([a-f\d\-]{30,}):(\d+)$};
+               if ($uuid ne $self->{svm}->{uuid}) {
+                       die "UUID mismatch on SVM path:\n",
+                           "expected: $self->{svm}->{uuid}\n",
+                           "     got: $uuid\n";
+               }
+               my $full_url = $self->{svm}->{source};
+               $full_url .= "/$self->{path}" if length $self->{path};
+               $log_entry{metadata} = "$full_url\@$r $uuid";
+               $log_entry{svm_revision} = $r;
+       } else {
+               $log_entry{metadata} = $self->full_url . "\@$rev " .
+                                      $self->ra->uuid;
+       }
        \%log_entry;
 }
 
@@ -1549,7 +1644,7 @@ sub _new {
                close $fh or croak $!;
        }
        bless { ref_id => $ref_id, dir => $dir, index => "$dir/index",
-               path => $path,
+               path => $path, config => "$ENV{GIT_DIR}/svn/config",
                db_path => "$dir/.rev_db", repo_id => $repo_id }, $class;
 }