gitweb: Add parsing of raw combined diff format to parse_difftree_raw_line

Add parsing line of raw combined diff ("git diff-tree -c/-cc" output)
as described in section "diff format for merges" in diff-format.txt
to parse_difftree_raw_line subroutine.

Returned hash (or hashref) has for combined diff 'nparents' key which
holds number of parents in a merge. At keys 'from_mode' and 'from_id'
there are arrayrefs holding modes and ids, respectively. There is no
'similarity' value, and there is only 'to_file' value and no
'from_file' value.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

gitweb/gitweb.perl

@@ -1495,6 +1495,17 @@ sub parse_difftree_raw_line {
 			$res{'file'} = unquote($7);
 		}
 	}
+	# '::100755 100755 100755 60e79ca1b01bc8b057abe17ddab484699a7f5fdb 94067cc5f73388f33722d52ae02f44692bc07490 94067cc5f73388f33722d52ae02f44692bc07490 MR	git-gui/git-gui.sh'
+	# combined diff (for merge commit)
+	elsif ($line =~ s/^(::+)((?:[0-7]{6} )+)((?:[0-9a-fA-F]{40} )+)([a-zA-Z]+)\t(.*)$//) {
+		$res{'nparents'}  = length($1);
+		$res{'from_mode'} = [ split(' ', $2) ];
+		$res{'to_mode'} = pop @{$res{'from_mode'}};
+		$res{'from_id'} = [ split(' ', $3) ];
+		$res{'to_id'} = pop @{$res{'from_id'}};
+		$res{'status'} = [ split('', $4) ];
+		$res{'to_file'} = unquote($5);
+	}
 	# 'c512b523472485aef4fff9e57b229d9d243c967f'
 	elsif ($line =~ m/^([0-9a-fA-F]{40})$/) {
 		$res{'commit'} = $1;