git-fmt-merge-msg.perl
#!/usr/bin/perl -w
#
# Copyright (c) 2005 Junio C Hamano
#
# Read .git/FETCH_HEAD and make a human readable merge message
# by grouping branches and tags together to form a single line.
use strict;
my @src;
my %src;
sub andjoin {
my ($label, $labels, $stuff) = @_;
my $l = scalar @$stuff;
my $m = '';
if ($l == 0) {
return ();
}
if ($l == 1) {
$m = "$label$stuff->[0]";
}
else {
$m = ("$labels" .
join (', ', @{$stuff}[0..$l-2]) .
" and $stuff->[-1]");
}
return ($m);
}
while (<>) {
my ($bname, $tname, $gname, $src);
chomp;
s/^[0-9a-f]* //;
next if (/^not-for-merge/);
s/^ //;
if (s/ of (.*)$//) {
$src = $1;
} else {
# Pulling HEAD
$src = $_;
$_ = 'HEAD';
}
if (! exists $src{$src}) {
push @src, $src;
$src{$src} = {
BRANCH => [],
TAG => [],
GENERIC => [],
# &1 == has HEAD.
# &2 == has others.
HEAD_STATUS => 0,
};
}
if (/^branch (.*)$/) {
push @{$src{$src}{BRANCH}}, $1;
$src{$src}{HEAD_STATUS} |= 2;
}
elsif (/^tag (.*)$/) {
push @{$src{$src}{TAG}}, $1;
$src{$src}{HEAD_STATUS} |= 2;
}
elsif (/^HEAD$/) {
$src{$src}{HEAD_STATUS} |= 1;
}
else {
push @{$src{$src}{GENERIC}}, $_;
$src{$src}{HEAD_STATUS} |= 2;
}
}
my @msg;
for my $src (@src) {
if ($src{$src}{HEAD_STATUS} == 1) {
# Only HEAD is fetched, nothing else.
push @msg, $src;
next;
}
my @this;
if ($src{$src}{HEAD_STATUS} == 3) {
# HEAD is fetched among others.
push @this, andjoin('', '', ['HEAD']);
}
push @this, andjoin("branch ", "branches ",
$src{$src}{BRANCH});
push @this, andjoin("tag ", "tags ",
$src{$src}{TAG});
push @this, andjoin("commit ", "commits ",
$src{$src}{GENERIC});
my $this = join(', ', @this);
if ($src ne '.') {
$this .= " of $src";
}
push @msg, $this;
}
print "Merge ", join("; ", @msg), "\n";