#!/bin/bash
# (C) 2004 Thomas Bleher <ThomasBleher@gmx.de> under the GNU GPL v2
# clean up a patch between a cvs tree and an arch tree with taglines
# just pipe your patch through this...
#
# this small script can be used to synchronize an arch-archive with a
# cvs repository. assuming the codebase is identical except taglines
# Usage: diff -urN arch/ cvs/ | cleanup-patch | patch -d arch/ -p1
# the above line merges all changes from cvs into arch

# first filter out all control files
filterdiff -x '*/CVS/*' -x '*/.arch-i*' -x '*/{arch}/*' -x '*/,,*' -x '*/++log*' | filterdiff | \
perl -0 -w -ne '# slurp the whole patch in and mangle it
for my $file (split(/(?=\n--- )/)) { # split into files
	for (split(/\n(?=@@ )/m, $file)) { # split into chunks (starting with @@)
		if (not /^@/) {
			# the header, just pass it through
			$data = $_;
		} else {
			# the cvs version doesnt have arch-tags; filter them from the diff
			if (s/\n-\n-(# arch-tag: [-a-z0-9]+)(.*)/$2\n \n $1/s     # arch-tag with preceding blank line
			   ||  s/\n-(# arch-tag: [-a-z0-9]+)(.*)/$2\n+\n $1/s) {  # single line arch-tag
				s/^(@@ -\d+,\d+ \+\d+,)(\d+)( @@\n)/$1.($2 + 2).$3/me; # adjust line count in patch
			}
			s/^@@.*?@@(\n[ \\].*)+$//g; # delete hunks that are now empty
			if (not /^$/) {
				$data .= "\n".$_;
			}
		}	
	}
	print $data unless ($data =~ /^\n---.*\n\+\+\+.*$/);
}
' | \
filterdiff | interdiff -U 3 /dev/null /proc/self/fd/0 | filterdiff
# some final cleanup