git-shove

#!/usr/bin/env perl
#=======================================================================
#	Shove one or more commits from the current branch onto another,
#	then merge it back in.
#
#	Suppose you have a work branch and are working on a feature
#	based from master.  You've tested the latest commit(s) on the
#	work branch, but they really belong on the feature branch.
#=======================================================================
use strict;
use Getopt::Long;

GetOptions()
    and @ARGV >= 1 and @ARGV <= 2
    or die "Usage: $0 to-branch [from-rev]\n";
my($to_branch,$from_rev) = @ARGV;
$from_rev ||= 'HEAD';

my $work_branch = git('rev-parse','--abbrev-ref','HEAD');
my $from_hash = git('rev-parse',"$from_rev^");
my $to_hash = git('rev-parse','HEAD');

git('checkout', $to_branch);
git('cherry-pick', "$from_hash..$to_hash");
git('checkout', $work_branch);
git('reset','--hard', $from_hash);
git('merge', $to_branch);

sub git {
    my(@args) = @_;
    my @cmd = ('git', @args);
    print STDERR join(' ',@cmd),"\n";
    open(my $git,'-|', @cmd)
	or die "Cannot open pipe from git: $!\n";
    my @lines = <$git>;
    close($git);
    if (wantarray) {
	return map {chomp} @lines;
    } else {
	chomp(my $out = join('', @lines));
	return $out;
    }
}