Index: user/des/fmerge/fmerge.pl
===================================================================
--- user/des/fmerge/fmerge.pl	(revision 197615)
+++ user/des/fmerge/fmerge.pl	(revision 197616)
@@ -1,304 +1,303 @@
 #!/usr/bin/perl -w
 #-
 # Copyright (c) 2009 Dag-Erling Coïdan Smørgrav
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer
 #    in this position and unchanged.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 # $FreeBSD$
 #
 
 use strict;
 use warnings;
 
 our $already;
 our $debug;
 our $pretend;
 
 our $src_branch = "head";	# where we merge from
-our $src_path;
+our $src_path;			# path relative to source branch
 our $src_url;			# source URL
 our $tgt_branch;		# where we merge to
-our $tgt_path;
+our $tgt_path;			# path relative to target branch
 our $tgt_dir = ".";		# target directory
+our $tgt_url;			# target URL
 
 our %revs = (0 => 0);
 our @ranges;
 
-our $svn_path;
-our $svn_url;
-our $svn_root;
-our $svn_branch;
+our $svn_path;			# path relative to branch
+our $svn_root;			# Repository root
 
 sub info(@) {
     print(STDERR join(' ', @_), "\n");
 }
 
 sub debug(@) {
     info(@_)
 	if $debug;
 }
 
 sub svn_check($@) {
     my ($cond, @msg) = @_;
     if (!$cond) {
 	info(@msg);
 	exit(1);
     }
 }
 
 sub svn_do(@) {
     my @argv = @_;
     unshift(@argv, '--dry-run')
 	if $pretend;
     info('svn', @argv);
     my $pid = fork();
     if ($pid == -1) {
 	die("fork(): $!\n");
     } elsif ($pid == 0) {
 	exec('svn', @argv);
 	die("exec(): $!\n");
     }
     waitpid($pid, 0);
     if ($? & 128) {
 	info("svn died with signal", $? & 128);
 	kill($? & 128, $$);
     } elsif ($?) {
 	info("svn returned error status", $? >> 8);
 	exit(1);
     }
 }
 
 sub svn_merge(@) {
     unshift(@_, '--record-only')
 	if $already;
     unshift(@_, 'merge');
     goto &svn_do;
 }
 
 sub svn_catch(@) {
     my (@argv) = @_;
     debug('svn', @argv);
     open(my $fh, '-|', 'svn', @argv)
 	or die("fmerge: could not run svn\n");
     return $fh;
 }
 
 sub examine() {
     my $fh = svn_catch("info", $tgt_dir);
     while (<$fh>) {
 	chomp();
 	my ($key, $value) = split(/:\s+/, $_, 2);
 	next unless $key && $value;
 	if ($key eq 'Path') {
 	    svn_check($value eq $tgt_dir, "path mismatch: $value != $tgt_dir");
 	} elsif ($key eq 'URL') {
-	    $svn_url = $value;
+	    $tgt_url = $value;
 	} elsif ($key eq 'Repository Root') {
 	    $svn_root = $value;
 	}
     }
     close($fh);
 
-    svn_check($svn_url =~ m@^\Q$svn_root\E(/.*)$@, "invalid svn URL: $svn_url");
+    svn_check($tgt_url =~ m@^\Q$svn_root\E(/.*)$@, "invalid svn URL: $tgt_url");
     $svn_path = $1;
 
     debug("guessing merge source / target directory");
     $fh = svn_catch('propget', 'svn:mergeinfo', $tgt_dir);
     while (<$fh>) {
 	chomp();
 	debug("'$_' =~ m\@^\Q/$src_branch\E((?:/[\\w.-]+)*):\@");
 	next unless m@^\Q/$src_branch\E((?:/[\w.-]+)*):@;
 	my $subdir = $1;
 	debug("'$svn_path' =~ m\@^((?:/[\\w.-]+)+)\Q$subdir\E\$\@");
 	next unless $svn_path =~ m@^((?:/[\w.-]+)+)\Q$subdir\E$@;
 	$svn_path = $subdir;
-	$svn_branch = $1;
+	$tgt_branch = $1;
 	last;
     }
     close($fh);
 
-    if (!$svn_branch) {
+    if (!$tgt_branch) {
 	# try to guess a stable / releng / release branch
-	debug("guessing source branch");
+	debug("guessing target branch");
 	debug("'$svn_path' =~ s\@^/([\\w+.-]/\\d+(?:\\.\\d+)*)/?\@\@");
-	$svn_path =~ s@^/(\w+/\d+(?:\.\d+)*)/?@@;
-	$svn_branch = $1;
+	$svn_path =~ s@^/(head|\w+/\d+(?:\.\d+)*)/?@@;
+	$tgt_branch = $1;
     }
-    svn_check($svn_branch, "unable to figure out source branch");
-    debug("svn_branch = '$svn_branch'");
+    svn_check($tgt_branch, "unable to figure out source branch");
+    debug("tgt_branch = '$tgt_branch'");
     debug("svn_path = '$svn_path'");
 }
 
 sub addrevs($$) {
     my ($m, $n) = @_;
     debug("adding range r$m:$n");
     if ($m > $n) {
 	for (my $i = $m; $i > $n; --$i) {
 	    $revs{$i} = -1;
 	}
     } else {
 	for (my $i = $m + 1; $i <= $n; ++$i)  {
 	    $revs{$i} = +1;
 	}
     }
 }
 
 sub revs2ranges() {
     my ($m, $n);
     # process in reverse, 0 acts as a sentinel
     foreach my $i (sort({ $b <=> $a } keys(%revs)), 0) {
 	if (!$m) {
 	    $m = $n = $i;
 	    next;
 	} elsif ($i == $m - 1 && $revs{$m} == +1 && $revs{$i} == +1) {
 	    $m = $i;
 	    next;
 	} elsif ($i == $m + 1 && $revs{$m} == -1 && $revs{$i} == -1) {
 	    $m = $i;
 	    next;
 	} else {
 	    if ($revs{$m} == +1) {
 		push(@ranges, [ $m - 1, $n ]);
 	    } elsif ($revs{$m} == -1) {
 		push(@ranges, [ $n, $m - 1 ]);
 	    }
 	    $m = $n = $i;
 	}
     }
     debug(join("\n  ", "ranges:", map { "r$_->[0]:$_->[1]" } @ranges));
 }
 
 sub printranges($) {
     my ($fh) = @_;
     my @print;
     foreach my $range (@ranges) {
 	my ($m, $n) = @{$range};
 	if ($n == $m + 1) {
 	    push(@print, $n);
 	} elsif ($n == $m - 1) {
 	    push(@print, "-$m"); 
 	} else {
 	    push(@print, "$m:$n");
 	}
     }
     print($fh "merging ", join(', ', @print), "\n")
 	if @print;
 }
 
 sub fmerge() {
     if (!@ranges) {
 	svn_merge("$svn_root/$src_branch/$svn_path", $tgt_dir);
     }
     foreach my $range (@ranges) {
 	my ($m, $n) = @{$range};
 	my $spec;
 	if ($n == $m + 1) {
 	    $spec = "-c$n";
 	} elsif ($n == $m - 1) {
 	    $spec = "-c-$n";
 	} else {
 	    $spec = "-r$m:$n";
 	}
 	svn_merge($spec, "$svn_root/$src_branch/$svn_path", $tgt_dir);
     }
 }
 
 sub usage() {
 
     print(STDERR "usage: fmerge REVISIONS [from BRANCH] [into DIR]\n");
     exit 1;
 }
 
 MAIN:{
     while (@ARGV) {
 	if ($ARGV[0] eq 'already') {
 	    shift;
 	    $already++;
 	} elsif ($ARGV[0] eq 'debug') {
 	    shift;
 	    $debug++;
 	} elsif ($ARGV[0] eq 'pretend') {
 	    shift;
 	    $pretend++;
 	} else {
 	    last;
 	}
     }
     if (@ARGV < 1) {
 	usage();
     }
     if ($ARGV[0] eq 'all') {
 	shift;
     } else {
 	while (@ARGV && $ARGV[0] =~ m/^[cr]?\d+([-:][cr]?\d+)?(,[cr]?\d+([-:][cr]?\d+)?)*$/) {
 	    foreach my $rev (split(',', $ARGV[0])) {
 		if ($rev =~ m/^[cr]?(\d+)$/) {
 		    addrevs($1 - 1, $1);
 		} elsif ($rev =~ m/^[cr]?-(\d+)$/) {
 		    addrevs($1, $1 - 1);
 		} elsif ($rev =~ m/^[cr]?(\d+)[-:][cr]?(\d+)$/) {
 		    if ($1 < $2) {
 			addrevs($1 - 1, $2);
 		    } else {
 			addrevs($1, $2 - 1);
 		    }
 		} else {
 		    usage();
 		}
 	    }
 	    shift;
 	}
     }
 
     while (@ARGV) {
 	if ($ARGV[0] eq 'from') {
 	    shift;
 	    if (@ARGV < 1) {
 		usage();
 	    }
 	    $src_branch = $ARGV[0];
 	    shift;
 	} elsif ($ARGV[0] eq 'into') {
 	    shift;
 	    if (@ARGV < 1) {
 		usage();
 	    }
 	    $tgt_dir = $ARGV[0];
 	    shift;
 	    if (!-d $tgt_dir) {
 		usage();
 	    }
 	} else {
 	    usage();
 	}
     }
 
     examine();
     revs2ranges();
     printranges(\*STDERR)
 	if $debug;
     fmerge();
 }
 
 1;