git-svn: add fetch --parent option

Signed-off-by Jason Merrill <[email protected]>

---
rebase fetches only the SVN parent of the current HEAD; it should be possible to do that with fetch as well, for instance to support rebasing with stg rebase rather than git rebase.

 Documentation/git-svn.txt |    3 +++
 git-svn.perl              |   18 ++++++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

Documentation/git-svn.txt +3 -0

index b7b1af8..85b2c8d 100644
@@ -97,6 +97,9 @@ COMMANDS
 	makes 'git-log' (even without --date=local) show the same times
 	that `svn log` would in the local timezone.
 
+--parent;;
+	Fetch only from the SVN parent of the current HEAD.
+
 This doesn't interfere with interoperating with the Subversion
 repository you cloned from, but if you wish for your local Git
 repository to be able to interoperate with someone else's local Git

git-svn.perl +14 -4

index d919798..cb718b8 100755
@@ -63,7 +63,7 @@ $sha1_short = qr/[a-f\d]{4,40}/;
 my ($_stdin, $_help, $_edit,
 	$_message, $_file,
 	$_template, $_shared,
-	$_version, $_fetch_all, $_no_rebase,
+	$_version, $_fetch_all, $_no_rebase, $_fetch_parent,
 	$_merge, $_strategy, $_dry_run, $_local,
 	$_prefix, $_no_checkout, $_url, $_verbose,
 	$_git_format, $_commit_url, $_tag);

@@ -112,6 +112,7 @@ my %cmd = (
 	fetch => [ \&cmd_fetch, "Download new revisions from SVN",
 			{ 'revision|r=s' => \$_revision,
 			  'fetch-all|all' => \$_fetch_all,
+			  'parent|p' => \$_fetch_parent,
 			   %fc_opts } ],
 	clone => [ \&cmd_clone, "Initialize and fetch revisions",
 			{ 'revision|r=s' => \$_revision,

@@ -381,12 +382,21 @@ sub cmd_fetch {
 	}
 	my ($remote) = @_;
 	if (@_ > 1) {
-		die "Usage: $0 fetch [--all] [svn-remote]\n";
+		die "Usage: $0 fetch [--all] [--parent] [svn-remote]\n";
 	}
-	$remote ||= $Git::SVN::default_repo_id;
-	if ($_fetch_all) {
+	if ($_fetch_parent) {
+		my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
+		unless ($gs) {
+			die "Unable to determine upstream SVN information from ",
+			    "working tree history\n";
+		}
+	        # just fetch, don't checkout.
+		$_no_checkout = 'true';
+		$_fetch_all ? $gs->fetch_all : $gs->fetch;
+	} elsif ($_fetch_all) {
 		cmd_multi_fetch();
 	} else {
+		$remote ||= $Git::SVN::default_repo_id;
 		Git::SVN::fetch_all($remote, Git::SVN::read_all_remotes());
 	}
 }