true built-in diff: run everything in-core.

diff --git a/git-fmt-merge-msg.perl b/git-fmt-merge-msg.perl
index f0f3100eb1c089efd990b71bb747f4dd0cd035f9..afe80e6321a1495c34139ec47af7d7d6aeb239fa 100755 (executable)
--- a/git-fmt-merge-msg.perl
+++ b/git-fmt-merge-msg.perl
@@ -27,10 +27,42 @@ sub andjoin {
        return ($m);
 }
 
+sub repoconfig {
+       my ($val) = qx{git-repo-config --get merge.summary};
+       return $val;
+}
+
+sub current_branch {
+       my ($bra) = qx{git-symbolic-ref HEAD};
+       chomp($bra);
+       $bra =~ s|^refs/heads/||;
+       if ($bra ne 'master') {
+               $bra = " into $bra";
+       } else {
+               $bra = "";
+       }
+       return $bra;
+}
+
+sub shortlog {
+       my ($tip) = @_;
+       my @result;
+       foreach ( qx{git-log --no-merges --topo-order --pretty=oneline $tip ^HEAD} ) {
+               s/^[0-9a-f]{40}\s+//;
+               push @result, $_;
+       }
+       die "git-log failed\n" if $?;
+       return @result;
+}
+
+my @origin = ();
 while (<>) {
-       my ($bname, $tname, $gname, $src);
+       my ($bname, $tname, $gname, $src, $sha1, $origin);
        chomp;
-       s/^[0-9a-f]*    //;
+       s/^([0-9a-f]*)  //;
+       $sha1 = $1;
+       next if (/^not-for-merge/);
+       s/^     //;
        if (s/ of (.*)$//) {
                $src = $1;
        } else {
@@ -50,19 +82,30 @@ sub andjoin {
                };
        }
        if (/^branch (.*)$/) {
+               $origin = $1;
                push @{$src{$src}{BRANCH}}, $1;
                $src{$src}{HEAD_STATUS} |= 2;
        }
        elsif (/^tag (.*)$/) {
+               $origin = $_;
                push @{$src{$src}{TAG}}, $1;
                $src{$src}{HEAD_STATUS} |= 2;
        }
        elsif (/^HEAD$/) {
+               $origin = $src;
                $src{$src}{HEAD_STATUS} |= 1;
        }
        else {
                push @{$src{$src}{GENERIC}}, $_;
                $src{$src}{HEAD_STATUS} |= 2;
+               $origin = $src;
+       }
+       if ($src eq '.' || $src eq $origin) {
+               $origin =~ s/^'(.*)'$/$1/;
+               push @origin, [$sha1, "$origin"];
+       }
+       else {
+               push @origin, [$sha1, "$origin of $src"];
        }
 }
 
@@ -86,8 +129,37 @@ sub andjoin {
                            $src{$src}{GENERIC});
        my $this = join(', ', @this);
        if ($src ne '.') {
-               $this .= " from $src";
+               $this .= " of $src";
        }
        push @msg, $this;
 }
-print "Merge ", join("; ", @msg), "\n";
+
+my $into = current_branch();
+
+print "Merge ", join("; ", @msg), $into, "\n";
+
+if (!repoconfig) {
+       exit(0);
+}
+
+# We limit the merge message to the latst 20 or so per each branch.
+my $limit = 20;
+
+for (@origin) {
+       my ($sha1, $name) = @$_;
+       my @log = shortlog($sha1);
+       if ($limit + 1 <= @log) {
+               print "\n* $name: (" . scalar(@log) . " commits)\n";
+       }
+       else {
+               print "\n* $name:\n";
+       }
+       my $cnt = 0;
+       for my $log (@log) {
+               if ($limit < ++$cnt) {
+                       print "  ...\n";
+                       last;
+               }
+               print "  $log";
+       }
+}