git-svn: Add --add-author-from option.

This option adds a From: line (based on the commit's author information)
at the beginning of the body of the commit log message when sending to
svn, if a From: or Signed-off-by: header does not exist.

This, combined with --use-log-author, can retain the author field of commits
through a round trip from git to svn and back.

Signed-off-by: Avery Pennarun <apenwarr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-svn.perl b/git-svn.perl
index b70f8efaaa404d63c6a45486f8513348cbb368f5..262acd9b365aba6ce5a0e1623e95cefd9c867a45 100755 (executable)
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -82,6 +82,7 @@ my %fc_opts = ( 'follow-parent|follow!' => \$Git::SVN::_follow_parent,
                'repack-flags|repack-args|repack-opts=s' =>
                   \$Git::SVN::_repack_flags,
                'use-log-author' => \$Git::SVN::_use_log_author,
+               'add-author-from' => \$Git::SVN::_add_author_from,
                %remote_opts );
 
 my ($_trunk, $_tags, $_branches, $_stdlayout);
@@ -1011,17 +1012,28 @@ sub get_commit_entry {
                my ($msg_fh, $ctx) = command_output_pipe('cat-file',
                                                         $type, $treeish);
                my $in_msg = 0;
+               my $author;
+               my $saw_from = 0;
                while (<$msg_fh>) {
                        if (!$in_msg) {
                                $in_msg = 1 if (/^\s*$/);
+                               $author = $1 if (/^author (.*>)/);
                        } elsif (/^git-svn-id: /) {
                                # skip this for now, we regenerate the
                                # correct one on re-fetch anyways
                                # TODO: set *:merge properties or like...
                        } else {
+                               if (/^From:/ || /^Signed-off-by:/) {
+                                       $saw_from = 1;
+                               }
                                print $log_fh $_ or croak $!;
                        }
                }
+               if ($Git::SVN::_add_author_from && defined($author)
+                   && !$saw_from) {
+                       print $log_fh "\nFrom: $author\n"
+                             or croak $!;
+               }
                command_close_pipe($msg_fh, $ctx);
        }
        close $log_fh or croak $!;
@@ -1248,7 +1260,7 @@ use constant rev_map_fmt => 'NH40';
 use vars qw/$default_repo_id $default_ref_id $_no_metadata $_follow_parent
             $_repack $_repack_flags $_use_svm_props $_head
             $_use_svnsync_props $no_reuse_existing $_minimize_url
-           $_use_log_author/;
+           $_use_log_author $_add_author_from/;
 use Carp qw/croak/;
 use File::Path qw/mkpath/;
 use File::Copy qw/copy/;