Update2: An attempt at recognition of merges

Overall, message subjects should be more descriptive.

diff --git a/update2 b/update2
index 32426c897a1f3dfca1e874db2b7dc880a2ec6e45..093919fe270224adc2f989d593d0a3731e9ea8da 100755 (executable)
--- a/update2
+++ b/update2
@@ -57,6 +57,21 @@ sub scan_branches() {
        return;
 }
 
+sub scan_commits() {
+       my @commits = ();
+       for (`git rev-list $old..$new --pretty=format:"# %H (%P) %s"`) {
+               chomp;
+               /^# / or next;
+               my ($hash, $parents, $subject) = m{^# (\S+) \(([^)]*)\) (.*)} or die;
+               push @commits, {
+                       hash => $hash,
+                       parents => [ split /\s+/, $parents ],
+                       subject => $subject,
+               };
+       }
+       return @commits;
+}
+
 sub most_recent() {
        print $out "Most recent commits:\n\n";
        system 'git', 'rev-list', @rev_list_options, '--max-count=20', $new;
@@ -86,22 +101,38 @@ if ($old =~ /^0+$/) {
        my $lca = `git merge-base $old $new`; die if $?;
        chomp $lca;
        if ($lca eq $old) {
-               # Fast forward
-               # Scan all commits first and construct subject
-               my @commits = `git rev-list $old..$new --pretty=oneline --no-abbrev --no-merges`; $? and die;
+               # Fast forward ... scan all objects
+               my @commits = scan_commits();
+               my @nonmerges = grep { @{$_->{parents}} == 1 } @commits;
                @commits or exit;
-               my $c = $commits[0];
-               chomp $c;
-               $c =~ s{^\S+\s+}{};
-               $subj .= " $c";
+
+               # Construct subject
+               # Try to recognize simple merges and display them as such
+               my $c0 = $commits[0];
+               my $n0 = $nonmerges[0];
+               my $c0p = $c0->{parents};
+               if (@{$c0p} == 2 &&
+                   $c0->{subject} =~ m{^\s*Merge branch '([^']*)'} &&
+                   $1 ne $ref &&
+                   ($c0p->[0] eq $old || $c0p->[1] eq $old)) {
+                       # Pushed a merge of a foreign branch to the current one
+                       $subj .= ' ' . $c0->{subject};
+               } elsif ($n0) {
+                       # Otherwise take the subject of the first non-merge commit
+                       $subj .= ' ' . $n0->{subject};
+               } else {
+                       # If there is none, take the first merge
+                       $subj .= ' ' . $c0->{subject};
+               }
+
                print $out "Push to branch $ref ($old -> $new)\n\n";
 
                # If there are multiple commits, print an overall diffstat first
-               if (@commits > 1) {
-                       $subj .= ' [...]';
-                       print $out "Overall diffstat:\n\n";
+               if (@nonmerges > 1) {
+                       $subj .= ' [' . (scalar @commits) . ' commits]';
+                       print $out 'Pushed ', (scalar @commits), " commits. Overall diffstat:\n\n";
                        system 'git', 'diff', '--stat', $old, $new;
-                       print $out "\nCommits:\n\n";
+                       print $out "\n";
                }
                my $pos_after_header = output_size();