[PATCH 5/6] gitweb: Add links to blobdiffs in from-file/to-file header for merges

[Jakub Narebski <jnareb@gmail.com>]

Add links to diff to file ('blobdiff' view) for each of individual
versions of the file in a merge commit to the from-file/to-file header
in the patch part of combined 'commitdiff' view for merges.

The from-file/to-file header for combined diff now looks like:

  --- _1_/_git-gui/git-gui.sh_
  --- _2_/_git-gui.sh_
  +++ b/_git-gui/git-gui.sh_

where _<filename>_ link is link to appropriate version of a file
('blob' view), and _<n>_ is link to respective diff to mentioned
version of a file ('blobdiff' view). There is even hint provided in
the form of title attribute.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
---
As requested by Junio C Hamano and Petr "Pasky" Baudis in:
  Message-ID: <7v1wh1en8k.fsf@assigned-by-dhcp.cox.net>
  Message-ID: <20070528132959.GT4489@pasky.or.cz>

I don't know if the link placement is best possible; I tried for
combined diff output be similar to ordinary diff output, but also
provide reqeusted additional functionality (which does not make
sense for ordinary diff). You have to know ehere to search for
the link.

 gitweb/gitweb.perl |   17 ++++++++++++++---
 1 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 13114bc..c7acfad 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -1058,7 +1058,7 @@ sub format_extended_diff_header_line {
 
 # format from-file/to-file diff header
 sub format_diff_from_to_header {
-	my ($from_line, $to_line, $diffinfo, $from, $to) = @_;
+	my ($from_line, $to_line, $diffinfo, $from, $to, @parents) = @_;
 	my $line;
 	my $result = '';
 
@@ -1084,7 +1084,17 @@ sub format_diff_from_to_header {
 		for (my $i = 0; $i < $diffinfo->{'nparents'}; $i++) {
 			if ($from->{'href'}[$i]) {
 				$line = '--- ' .
-				        ($i+1) . "/" .
+				        $cgi->a({-href=>href(action=>"blobdiff",
+				                             hash_parent=>$diffinfo->{'from_id'}[$i],
+				                             hash_parent_base=>$parents[$i],
+				                             file_parent=>$from->{'file'}[$i],
+				                             hash=>$diffinfo->{'to_id'},
+				                             hash_base=>$hash,
+				                             file_name=>$to->{'file'}),
+				                 -class=>"path",
+				                 -title=>"diff" . ($i+1)},
+				                $i+1) .
+				        '/' .
 				        $cgi->a({-href=>$from->{'href'}[$i], -class=>"path"},
 				                esc_path($from->{'file'}[$i]));
 			} else {
@@ -3042,7 +3052,8 @@ sub git_patchset_body {
 		#assert($patch_line =~ m/^\+\+\+/) if DEBUG;
 
 		print format_diff_from_to_header($last_patch_line, $patch_line,
-		                                 $diffinfo, \%from, \%to);
+		                                 $diffinfo, \%from, \%to,
+		                                 @hash_parents);
 
 		# the patch itself
 	LINE: