Add 'git svn help [cmd]' which works outside a repo.

diff --git a/git-svn.perl b/git-svn.perl
index 33017974d0a098bdaff707ccf0e8660aa5009079..da1e1f64e9f3da06f687b447e448ad5bc6079072 100755 (executable)
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -219,6 +219,9 @@ BEGIN
                $cmd = $ARGV[$i];
                splice @ARGV, $i, 1;
                last;
+       } elsif ($ARGV[$i] eq 'help') {
+               $cmd = $ARGV[$i+1];
+               usage(0);
        }
 };
 
@@ -454,8 +457,22 @@ sub cmd_dcommit {
                'Cannot dcommit with a dirty index.  Commit your changes first, '
                . "or stash them with `git stash'.\n";
        $head ||= 'HEAD';
+
+       my $old_head;
+       if ($head ne 'HEAD') {
+               $old_head = eval {
+                       command_oneline([qw/symbolic-ref -q HEAD/])
+               };
+               if ($old_head) {
+                       $old_head =~ s{^refs/heads/}{};
+               } else {
+                       $old_head = eval { command_oneline(qw/rev-parse HEAD/) };
+               }
+               command(['checkout', $head], STDERR => 0);
+       }
+
        my @refs;
-       my ($url, $rev, $uuid, $gs) = working_head_info($head, \@refs);
+       my ($url, $rev, $uuid, $gs) = working_head_info('HEAD', \@refs);
        unless ($gs) {
                die "Unable to determine upstream SVN information from ",
                    "$head history.\nPerhaps the repository is empty.";
@@ -541,7 +558,7 @@ sub cmd_dcommit {
                        if (@diff) {
                                @refs = ();
                                my ($url_, $rev_, $uuid_, $gs_) =
-                                             working_head_info($head, \@refs);
+                                             working_head_info('HEAD', \@refs);
                                my ($linear_refs_, $parents_) =
                                              linearize_history($gs_, \@refs);
                                if (scalar(@$linear_refs) !=
@@ -579,6 +596,22 @@ sub cmd_dcommit {
                        }
                }
        }
+
+       if ($old_head) {
+               my $new_head = command_oneline(qw/rev-parse HEAD/);
+               my $new_is_symbolic = eval {
+                       command_oneline(qw/symbolic-ref -q HEAD/);
+               };
+               if ($new_is_symbolic) {
+                       print "dcommitted the branch ", $head, "\n";
+               } else {
+                       print "dcommitted on a detached HEAD because you gave ",
+                             "a revision argument.\n",
+                             "The rewritten commit is: ", $new_head, "\n";
+               }
+               command(['checkout', $old_head], STDERR => 0);
+       }
+
        unlink $gs->{index};
 }