git-svn: add support for pulling author from From: and Signed-off-by:

Add support for pulling the real author of a commit from the From:
and first Signed-off-by: fields of the SVN commit message.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Eric Wong <normalperson@yhbt.net>

git-svn.perl

@@ -81,6 +81,7 @@ my %fc_opts = ( 'follow-parent|follow!' => \$Git::SVN::_follow_parent,
 		'quiet|q' => \$_q,
 		'repack-flags|repack-args|repack-opts=s' =>
 		   \$Git::SVN::_repack_flags,
+		'use-log-author' => \$Git::SVN::_use_log_author,
 		%remote_opts );
 
 my ($_trunk, $_tags, $_branches, $_stdlayout);
@@ -1220,7 +1221,8 @@ use strict;
 use warnings;
 use vars qw/$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_svnsync_props $no_reuse_existing $_minimize_url
+	    $_use_log_author/;
 use Carp qw/croak/;
 use File::Path qw/mkpath/;
 use File::Copy qw/copy/;
@@ -2060,11 +2062,17 @@ sub do_git_commit {
 		croak "$log_entry->{revision} = $c already exists! ",
 		      "Why are we refetching it?\n";
 	}
-	$ENV{GIT_AUTHOR_NAME} = $ENV{GIT_COMMITTER_NAME} = $log_entry->{name};
+	$ENV{GIT_AUTHOR_NAME} = $log_entry->{name};
-	$ENV{GIT_AUTHOR_EMAIL} = $ENV{GIT_COMMITTER_EMAIL} =
+	$ENV{GIT_AUTHOR_EMAIL} = $log_entry->{email};
-	                                                  $log_entry->{email};
 	$ENV{GIT_AUTHOR_DATE} = $ENV{GIT_COMMITTER_DATE} = $log_entry->{date};
 
+	$ENV{GIT_COMMITTER_NAME} = (defined $log_entry->{commit_name})
+						? $log_entry->{commit_name}
+						: $log_entry->{name};
+	$ENV{GIT_COMMITTER_EMAIL} = (defined $log_entry->{commit_email})
+						? $log_entry->{commit_email}
+						: $log_entry->{email};
+
 	my $tree = $log_entry->{tree};
 	if (!defined $tree) {
 		$tree = $self->tmp_index_do(sub {
@@ -2352,7 +2360,17 @@ sub make_log_entry {
 	$log_entry{log} .= "\n";
 	my $author = $log_entry{author} = check_author($log_entry{author});
 	my ($name, $email) = defined $::users{$author} ? @{$::users{$author}}
-	                                               : ($author, undef);
+						       : ($author, undef);
+
+	my ($commit_name, $commit_email) = ($name, $email);
+	if ($_use_log_author) {
+		if ($log_entry{log} =~ /From:\s+(.*?)\s+<(.*)>\s*\n/) {
+			($name, $email) = ($1, $2);
+		} elsif ($log_entry{log} =~
+		                      /Signed-off-by:\s+(.*?)\s+<(.*)>\s*\n/) {
+			($name, $email) = ($1, $2);
+		}
+	}
 	if (defined $headrev && $self->use_svm_props) {
 		if ($self->rewrite_root) {
 			die "Can't have both 'useSvmProps' and 'rewriteRoot' ",
@@ -2375,23 +2393,28 @@ sub make_log_entry {
 		remove_username($full_url);
 		$log_entry{metadata} = "$full_url\@$r $uuid";
 		$log_entry{svm_revision} = $r;
-		$email ||= "$author\@$uuid"
+		$email ||= "$author\@$uuid";
+		$commit_email ||= "$author\@$uuid";
 	} elsif ($self->use_svnsync_props) {
 		my $full_url = $self->svnsync->{url};
 		$full_url .= "/$self->{path}" if length $self->{path};
 		remove_username($full_url);
 		my $uuid = $self->svnsync->{uuid};
 		$log_entry{metadata} = "$full_url\@$rev $uuid";
-		$email ||= "$author\@$uuid"
+		$email ||= "$author\@$uuid";
+		$commit_email ||= "$author\@$uuid";
 	} else {
 		my $url = $self->metadata_url;
 		remove_username($url);
 		$log_entry{metadata} = "$url\@$rev " .
 		                       $self->ra->get_uuid;
 		$email ||= "$author\@" . $self->ra->get_uuid;
+		$commit_email ||= "$author\@" . $self->ra->get_uuid;
 	}
 	$log_entry{name} = $name;
 	$log_entry{email} = $email;
+	$log_entry{commit_name} = $commit_name;
+	$log_entry{commit_email} = $commit_email;
 	\%log_entry;
 }