#!/usr/bin/perl -i.bak -p
# (C) 2004-2005, Mark A. Hillebrand <mah at cs dot uni-sb dot de>
# Purpose: does something similar to cvs2cl --accum
# Usage: Provide the ChangeLog name as first (single) argument
# First time usage: create initial ChangeLog via `svn log > ChangeLog'
# or `svn log --verbose > ChangeLog'
#
# TODO under certain circumstance, line 1 contains `No commit for revision 0.'
# - maybe handle this
if( $.==1 ) {
	$first=$_; # save first line (of hyphens) for possible later use
	$_='';	# don't print
} elsif( $.==2 ) {
	unless( m/^r(\d+)/ ) {
		rename "$ARGV.bak", $ARGV if defined $ARGV;
		die "?Parse error in line $.; stopping.\n";
	};
	$second=$_; # save line for later use
	$revision=$1; # save revision for later use
	$_='';	# don't print
} elsif( $.==3 ) {
	# Detect whether the ChangeLog was created with verbosity option
	$verbose = m/^Changed paths:$/ ? '--verbose' : '';
	# put $first line back in, if there was no new revision, otherwise,
	# the line of hyphens comes from the log command
	warn "svn log $verbose -r HEAD:@{[$revision+1]} 2>/dev/null\n";
	print `svn log $verbose -r HEAD:@{[$revision+1]} 2>/dev/null` || $first;
	$_ = $second.$_;	# always second and current (i.e., old third) line afterwards
}