I recently decided to try maintaining a Debian package (bibutils) without committing any patches to Git. One of the disadvantages of this approach is that the patches for upstream are not nicely sorted out in ./debian/patches. I decided to write a little tool to sort out which commits should be sent to upstream. I'm not too happy about the length of it, or the name "git-classify", but I'm posting in case someone has some suggestions. Or maybe somebody finds this useful.

#!/usr/bin/perl

use strict;

my $upstreamonly=0;

if ($ARGV[0] eq "-u"){
  $upstreamonly=1;
  shift (@ARGV);
}

open(GIT,"git log -z --format=\"%n%x00%H\" --name-only  @ARGV|");

# throw away blank line at the beginning.
$_=<GIT>;

my $sha="";
LINE: while(<GIT>){

  chomp();

  next LINE if (m/^\s*$/);

  if (m/^\x0([0-9a-fA-F]+)/){
    $sha=$1;
  } else {
    my $debian=0;
    my $upstream=0;

    foreach my $word  ( split("\x00",$_) ) {
      if  ($word=~m@^debian/@) {
        $debian++;
      } elsif (length($word)>0)  {
        $upstream++;
      }
    }

    if (!$upstreamonly){
      print "$sha\t";
      print "MIXED" if ($upstream>0  && $debian>0);
      print "upstream" if ($upstream>0  && $debian==0);
      print "debian" if ($upstream==0  && $debian>0);
      print "\n";
    } else {
      print "$sha\n" if ($upstream>0  && $debian==0);
    }

  }
}

=pod

=head1 Name
git-classify  - Classify commits as upstream, debian, or MIXED

=head1 Synopsis

=over

=item B<git classify> [I<-u>] [I<arguments for git-log>]

=back

=head1 Description

Classify a range of commits (specified as for git-log) as I<upstream>
(touching only files outside ./debian), I<debian> (touching files only
inside ./debian) or I<MIXED>. Presumably these last kind are to be
discouraged.

=head2 Options

=over

=item B<-u> output only the SHA1 hashes of upstream commits (as
      defined above).

=back

=head1 Examples

Generate all likely patches to send upstream
   
     git classify -u $SHA..HEAD | xargs -L1 git format-patch -1