Extract Git::SVN from git-svn into its own .pm file.

Except for adding the 1; at the end, this is a straight copy & paste.

Tests still pass, but its doubtful Git::SVN will compile on its own
without git-svn being loaded.  Next commit will fix that.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Eric Wong <normalperson@yhbt.net>

2 files changed, 2320 insertions, 0 deletions

diff --git a/perl/Git/SVN.pm b/perl/Git/SVN.pm
new file mode 100644
index 000000000..c71c04198
--- /dev/null
+++ b/perl/Git/SVN.pm
@@ -0,0 +1,2319 @@
+package Git::SVN;
+use strict;
+use warnings;
+use Fcntl qw/:DEFAULT :seek/;
+use constant rev_map_fmt => 'NH40';
+use vars qw/$default_repo_id $default_ref_id $_no_metadata $_follow_parent
+            $_repack $_repack_flags $_use_svm_props $_head
+            $_use_svnsync_props $no_reuse_existing $_minimize_url
+	    $_use_log_author $_add_author_from $_localtime/;
+use Carp qw/croak/;
+use File::Path qw/mkpath/;
+use File::Copy qw/copy/;
+use IPC::Open3;
+use Time::Local;
+use Memoize;  # core since 5.8.0, Jul 2002
+use Memoize::Storable;
+use POSIX qw(:signal_h);
+
+use Git qw(
+    command
+    command_oneline
+    command_noisy
+    command_output_pipe
+    command_close_pipe
+);
+use Git::SVN::Utils qw(fatal can_compress);
+
+my $can_use_yaml;
+BEGIN {
+	$can_use_yaml = eval { require Git::SVN::Memoize::YAML; 1};
+}
+
+my ($_gc_nr, $_gc_period);
+
+# properties that we do not log:
+my %SKIP_PROP;
+BEGIN {
+	%SKIP_PROP = map { $_ => 1 } qw/svn:wc:ra_dav:version-url
+	                                svn:special svn:executable
+	                                svn:entry:committed-rev
+	                                svn:entry:last-author
+	                                svn:entry:uuid
+	                                svn:entry:committed-date/;
+
+	# some options are read globally, but can be overridden locally
+	# per [svn-remote "..."] section.  Command-line options will *NOT*
+	# override options set in an [svn-remote "..."] section
+	no strict 'refs';
+	for my $option (qw/follow_parent no_metadata use_svm_props
+			   use_svnsync_props/) {
+		my $key = $option;
+		$key =~ tr/_//d;
+		my $prop = "-$option";
+		*$option = sub {
+			my ($self) = @_;
+			return $self->{$prop} if exists $self->{$prop};
+			my $k = "svn-remote.$self->{repo_id}.$key";
+			eval { command_oneline(qw/config --get/, $k) };
+			if ($@) {
+				$self->{$prop} = ${"Git::SVN::_$option"};
+			} else {
+				my $v = command_oneline(qw/config --bool/,$k);
+				$self->{$prop} = $v eq 'false' ? 0 : 1;
+			}
+			return $self->{$prop};
+		}
+	}
+}
+
+
+my (%LOCKFILES, %INDEX_FILES);
+END {
+	unlink keys %LOCKFILES if %LOCKFILES;
+	unlink keys %INDEX_FILES if %INDEX_FILES;
+}
+
+sub resolve_local_globs {
+	my ($url, $fetch, $glob_spec) = @_;
+	return unless defined $glob_spec;
+	my $ref = $glob_spec->{ref};
+	my $path = $glob_spec->{path};
+	foreach (command(qw#for-each-ref --format=%(refname) refs/#)) {
+		next unless m#^$ref->{regex}$#;
+		my $p = $1;
+		my $pathname = desanitize_refname($path->full_path($p));
+		my $refname = desanitize_refname($ref->full_path($p));
+		if (my $existing = $fetch->{$pathname}) {
+			if ($existing ne $refname) {
+				die "Refspec conflict:\n",
+				    "existing: $existing\n",
+				    " globbed: $refname\n";
+			}
+			my $u = (::cmt_metadata("$refname"))[0];
+			$u =~ s!^\Q$url\E(/|$)!! or die
+			  "$refname: '$url' not found in '$u'\n";
+			if ($pathname ne $u) {
+				warn "W: Refspec glob conflict ",
+				     "(ref: $refname):\n",
+				     "expected path: $pathname\n",
+				     "    real path: $u\n",
+				     "Continuing ahead with $u\n";
+				next;
+			}
+		} else {
+			$fetch->{$pathname} = $refname;
+		}
+	}
+}
+
+sub parse_revision_argument {
+	my ($base, $head) = @_;
+	if (!defined $::_revision || $::_revision eq 'BASE:HEAD') {
+		return ($base, $head);
+	}
+	return ($1, $2) if ($::_revision =~ /^(\d+):(\d+)$/);
+	return ($::_revision, $::_revision) if ($::_revision =~ /^\d+$/);
+	return ($head, $head) if ($::_revision eq 'HEAD');
+	return ($base, $1) if ($::_revision =~ /^BASE:(\d+)$/);
+	return ($1, $head) if ($::_revision =~ /^(\d+):HEAD$/);
+	die "revision argument: $::_revision not understood by git-svn\n";
+}
+
+sub fetch_all {
+	my ($repo_id, $remotes) = @_;
+	if (ref $repo_id) {
+		my $gs = $repo_id;
+		$repo_id = undef;
+		$repo_id = $gs->{repo_id};
+	}
+	$remotes ||= read_all_remotes();
+	my $remote = $remotes->{$repo_id} or
+	             die "[svn-remote \"$repo_id\"] unknown\n";
+	my $fetch = $remote->{fetch};
+	my $url = $remote->{url} or die "svn-remote.$repo_id.url not defined\n";
+	my (@gs, @globs);
+	my $ra = Git::SVN::Ra->new($url);
+	my $uuid = $ra->get_uuid;
+	my $head = $ra->get_latest_revnum;
+
+	# ignore errors, $head revision may not even exist anymore
+	eval { $ra->get_log("", $head, 0, 1, 0, 1, sub { $head = $_[1] }) };
+	warn "W: $@\n" if $@;
+
+	my $base = defined $fetch ? $head : 0;
+
+	# read the max revs for wildcard expansion (branches/*, tags/*)
+	foreach my $t (qw/branches tags/) {
+		defined $remote->{$t} or next;
+		push @globs, @{$remote->{$t}};
+
+		my $max_rev = eval { tmp_config(qw/--int --get/,
+		                         "svn-remote.$repo_id.${t}-maxRev") };
+		if (defined $max_rev && ($max_rev < $base)) {
+			$base = $max_rev;
+		} elsif (!defined $max_rev) {
+			$base = 0;
+		}
+	}
+
+	if ($fetch) {
+		foreach my $p (sort keys %$fetch) {
+			my $gs = Git::SVN->new($fetch->{$p}, $repo_id, $p);
+			my $lr = $gs->rev_map_max;
+			if (defined $lr) {
+				$base = $lr if ($lr < $base);
+			}
+			push @gs, $gs;
+		}
+	}
+
+	($base, $head) = parse_revision_argument($base, $head);
+	$ra->gs_fetch_loop_common($base, $head, \@gs, \@globs);
+}
+
+sub read_all_remotes {
+	my $r = {};
+	my $use_svm_props = eval { command_oneline(qw/config --bool
+	    svn.useSvmProps/) };
+	$use_svm_props = $use_svm_props eq 'true' if $use_svm_props;
+	my $svn_refspec = qr{\s*(.*?)\s*:\s*(.+?)\s*};
+	foreach (grep { s/^svn-remote\.// } command(qw/config -l/)) {
+		if (m!^(.+)\.fetch=$svn_refspec$!) {
+			my ($remote, $local_ref, $remote_ref) = ($1, $2, $3);
+			die("svn-remote.$remote: remote ref '$remote_ref' "
+			    . "must start with 'refs/'\n")
+				unless $remote_ref =~ m{^refs/};
+			$local_ref = uri_decode($local_ref);
+			$r->{$remote}->{fetch}->{$local_ref} = $remote_ref;
+			$r->{$remote}->{svm} = {} if $use_svm_props;
+		} elsif (m!^(.+)\.usesvmprops=\s*(.*)\s*$!) {
+			$r->{$1}->{svm} = {};
+		} elsif (m!^(.+)\.url=\s*(.*)\s*$!) {
+			$r->{$1}->{url} = $2;
+		} elsif (m!^(.+)\.pushurl=\s*(.*)\s*$!) {
+			$r->{$1}->{pushurl} = $2;
+		} elsif (m!^(.+)\.ignore-refs=\s*(.*)\s*$!) {
+			$r->{$1}->{ignore_refs_regex} = $2;
+		} elsif (m!^(.+)\.(branches|tags)=$svn_refspec$!) {
+			my ($remote, $t, $local_ref, $remote_ref) =
+			                                     ($1, $2, $3, $4);
+			die("svn-remote.$remote: remote ref '$remote_ref' ($t) "
+			    . "must start with 'refs/'\n")
+				unless $remote_ref =~ m{^refs/};
+			$local_ref = uri_decode($local_ref);
+			my $rs = {
+			    t => $t,
+			    remote => $remote,
+			    path => Git::SVN::GlobSpec->new($local_ref, 1),
+			    ref => Git::SVN::GlobSpec->new($remote_ref, 0) };
+			if (length($rs->{ref}->{right}) != 0) {
+				die "The '*' glob character must be the last ",
+				    "character of '$remote_ref'\n";
+			}
+			push @{ $r->{$remote}->{$t} }, $rs;
+		}
+	}
+
+	map {
+		if (defined $r->{$_}->{svm}) {
+			my $svm;
+			eval {
+				my $section = "svn-remote.$_";
+				$svm = {
+					source => tmp_config('--get',
+					    "$section.svm-source"),
+					replace => tmp_config('--get',
+					    "$section.svm-replace"),
+				}
+			};
+			$r->{$_}->{svm} = $svm;
+		}
+	} keys %$r;
+
+	foreach my $remote (keys %$r) {
+		foreach ( grep { defined $_ }
+			  map { $r->{$remote}->{$_} } qw(branches tags) ) {
+			foreach my $rs ( @$_ ) {
+				$rs->{ignore_refs_regex} =
+				    $r->{$remote}->{ignore_refs_regex};
+			}
+		}
+	}
+
+	$r;
+}
+
+sub init_vars {
+	$_gc_nr = $_gc_period = 1000;
+	if (defined $_repack || defined $_repack_flags) {
+	       warn "Repack options are obsolete; they have no effect.\n";
+	}
+}
+
+sub verify_remotes_sanity {
+	return unless -d $ENV{GIT_DIR};
+	my %seen;
+	foreach (command(qw/config -l/)) {
+		if (m!^svn-remote\.(?:.+)\.fetch=.*:refs/remotes/(\S+)\s*$!) {
+			if ($seen{$1}) {
+				die "Remote ref refs/remote/$1 is tracked by",
+				    "\n  \"$_\"\nand\n  \"$seen{$1}\"\n",
+				    "Please resolve this ambiguity in ",
+				    "your git configuration file before ",
+				    "continuing\n";
+			}
+			$seen{$1} = $_;
+		}
+	}
+}
+
+sub find_existing_remote {
+	my ($url, $remotes) = @_;
+	return undef if $no_reuse_existing;
+	my $existing;
+	foreach my $repo_id (keys %$remotes) {
+		my $u = $remotes->{$repo_id}->{url} or next;
+		next if $u ne $url;
+		$existing = $repo_id;
+		last;
+	}
+	$existing;
+}
+
+sub init_remote_config {
+	my ($self, $url, $no_write) = @_;
+	$url =~ s!/+$!!; # strip trailing slash
+	my $r = read_all_remotes();
+	my $existing = find_existing_remote($url, $r);
+	if ($existing) {
+		unless ($no_write) {
+			print STDERR "Using existing ",
+				     "[svn-remote \"$existing\"]\n";
+		}
+		$self->{repo_id} = $existing;
+	} elsif ($_minimize_url) {
+		my $min_url = Git::SVN::Ra->new($url)->minimize_url;
+		$existing = find_existing_remote($min_url, $r);
+		if ($existing) {
+			unless ($no_write) {
+				print STDERR "Using existing ",
+					     "[svn-remote \"$existing\"]\n";
+			}
+			$self->{repo_id} = $existing;
+		}
+		if ($min_url ne $url) {
+			unless ($no_write) {
+				print STDERR "Using higher level of URL: ",
+					     "$url => $min_url\n";
+			}
+			my $old_path = $self->{path};
+			$self->{path} = $url;
+			$self->{path} =~ s!^\Q$min_url\E(/|$)!!;
+			if (length $old_path) {
+				$self->{path} .= "/$old_path";
+			}
+			$url = $min_url;
+		}
+	}
+	my $orig_url;
+	if (!$existing) {
+		# verify that we aren't overwriting anything:
+		$orig_url = eval {
+			command_oneline('config', '--get',
+					"svn-remote.$self->{repo_id}.url")
+		};
+		if ($orig_url && ($orig_url ne $url)) {
+			die "svn-remote.$self->{repo_id}.url already set: ",
+			    "$orig_url\nwanted to set to: $url\n";
+		}
+	}
+	my ($xrepo_id, $xpath) = find_ref($self->refname);
+	if (!$no_write && defined $xpath) {
+		die "svn-remote.$xrepo_id.fetch already set to track ",
+		    "$xpath:", $self->refname, "\n";
+	}
+	unless ($no_write) {
+		command_noisy('config',
+			      "svn-remote.$self->{repo_id}.url", $url);
+		$self->{path} =~ s{^/}{};
+		$self->{path} =~ s{%([0-9A-F]{2})}{chr hex($1)}ieg;
+		command_noisy('config', '--add',
+			      "svn-remote.$self->{repo_id}.fetch",
+			      "$self->{path}:".$self->refname);
+	}
+	$self->{url} = $url;
+}
+
+sub find_by_url { # repos_root and, path are optional
+	my ($class, $full_url, $repos_root, $path) = @_;
+
+	return undef unless defined $full_url;
+	remove_username($full_url);
+	remove_username($repos_root) if defined $repos_root;
+	my $remotes = read_all_remotes();
+	if (defined $full_url && defined $repos_root && !defined $path) {
+		$path = $full_url;
+		$path =~ s#^\Q$repos_root\E(?:/|$)##;
+	}
+	foreach my $repo_id (keys %$remotes) {
+		my $u = $remotes->{$repo_id}->{url} or next;
+		remove_username($u);
+		next if defined $repos_root && $repos_root ne $u;
+
+		my $fetch = $remotes->{$repo_id}->{fetch} || {};
+		foreach my $t (qw/branches tags/) {
+			foreach my $globspec (@{$remotes->{$repo_id}->{$t}}) {
+				resolve_local_globs($u, $fetch, $globspec);
+			}
+		}
+		my $p = $path;
+		my $rwr = rewrite_root({repo_id => $repo_id});
+		my $svm = $remotes->{$repo_id}->{svm}
+			if defined $remotes->{$repo_id}->{svm};
+		unless (defined $p) {
+			$p = $full_url;
+			my $z = $u;
+			my $prefix = '';
+			if ($rwr) {
+				$z = $rwr;
+				remove_username($z);
+			} elsif (defined $svm) {
+				$z = $svm->{source};
+				$prefix = $svm->{replace};
+				$prefix =~ s#^\Q$u\E(?:/|$)##;
+				$prefix =~ s#/$##;
+			}
+			$p =~ s#^\Q$z\E(?:/|$)#$prefix# or next;
+		}
+		foreach my $f (keys %$fetch) {
+			next if $f ne $p;
+			return Git::SVN->new($fetch->{$f}, $repo_id, $f);
+		}
+	}
+	undef;
+}
+
+sub init {
+	my ($class, $url, $path, $repo_id, $ref_id, $no_write) = @_;
+	my $self = _new($class, $repo_id, $ref_id, $path);
+	if (defined $url) {
+		$self->init_remote_config($url, $no_write);
+	}
+	$self;
+}
+
+sub find_ref {
+	my ($ref_id) = @_;
+	foreach (command(qw/config -l/)) {
+		next unless m!^svn-remote\.(.+)\.fetch=
+		              \s*(.*?)\s*:\s*(.+?)\s*$!x;
+		my ($repo_id, $path, $ref) = ($1, $2, $3);
+		if ($ref eq $ref_id) {
+			$path = '' if ($path =~ m#^\./?#);
+			return ($repo_id, $path);
+		}
+	}
+	(undef, undef, undef);
+}
+
+sub new {
+	my ($class, $ref_id, $repo_id, $path) = @_;
+	if (defined $ref_id && !defined $repo_id && !defined $path) {
+		($repo_id, $path) = find_ref($ref_id);
+		if (!defined $repo_id) {
+			die "Could not find a \"svn-remote.*.fetch\" key ",
+			    "in the repository configuration matching: ",
+			    "$ref_id\n";
+		}
+	}
+	my $self = _new($class, $repo_id, $ref_id, $path);
+	if (!defined $self->{path} || !length $self->{path}) {
+		my $fetch = command_oneline('config', '--get',
+		                            "svn-remote.$repo_id.fetch",
+		                            ":$ref_id\$") or
+		     die "Failed to read \"svn-remote.$repo_id.fetch\" ",
+		         "\":$ref_id\$\" in config\n";
+		($self->{path}, undef) = split(/\s*:\s*/, $fetch);
+	}
+	$self->{path} =~ s{/+}{/}g;
+	$self->{path} =~ s{\A/}{};
+	$self->{path} =~ s{/\z}{};
+	$self->{url} = command_oneline('config', '--get',
+	                               "svn-remote.$repo_id.url") or
+                  die "Failed to read \"svn-remote.$repo_id.url\" in config\n";
+	$self->{pushurl} = eval { command_oneline('config', '--get',
+	                          "svn-remote.$repo_id.pushurl") };
+	$self->rebuild;
+	$self;
+}
+
+sub refname {
+	my ($refname) = $_[0]->{ref_id} ;
+
+	# It cannot end with a slash /, we'll throw up on this because
+	# SVN can't have directories with a slash in their name, either:
+	if ($refname =~ m{/$}) {
+		die "ref: '$refname' ends with a trailing slash, this is ",
+		    "not permitted by git nor Subversion\n";
+	}
+
+	# It cannot have ASCII control character space, tilde ~, caret ^,
+	# colon :, question-mark ?, asterisk *, space, or open bracket [
+	# anywhere.
+	#
+	# Additionally, % must be escaped because it is used for escaping
+	# and we want our escaped refname to be reversible
+	$refname =~ s{([ \%~\^:\?\*\[\t])}{uc sprintf('%%%02x',ord($1))}eg;
+
+	# no slash-separated component can begin with a dot .
+	# /.* becomes /%2E*
+	$refname =~ s{/\.}{/%2E}g;
+
+	# It cannot have two consecutive dots .. anywhere
+	# .. becomes %2E%2E
+	$refname =~ s{\.\.}{%2E%2E}g;
+
+	# trailing dots and .lock are not allowed
+	# .$ becomes %2E and .lock becomes %2Elock
+	$refname =~ s{\.(?=$|lock$)}{%2E};
+
+	# the sequence @{ is used to access the reflog
+	# @{ becomes %40{
+	$refname =~ s{\@\{}{%40\{}g;
+
+	return $refname;
+}
+
+sub desanitize_refname {
+	my ($refname) = @_;
+	$refname =~ s{%(?:([0-9A-F]{2}))}{chr hex($1)}eg;
+	return $refname;
+}
+
+sub svm_uuid {
+	my ($self) = @_;
+	return $self->{svm}->{uuid} if $self->svm;
+	$self->ra;
+	unless ($self->{svm}) {
+		die "SVM UUID not cached, and reading remotely failed\n";
+	}
+	$self->{svm}->{uuid};
+}
+
+sub svm {
+	my ($self) = @_;
+	return $self->{svm} if $self->{svm};
+	my $svm;
+	# see if we have it in our config, first:
+	eval {
+		my $section = "svn-remote.$self->{repo_id}";
+		$svm = {
+		  source => tmp_config('--get', "$section.svm-source"),
+		  uuid => tmp_config('--get', "$section.svm-uuid"),
+		  replace => tmp_config('--get', "$section.svm-replace"),
+		}
+	};
+	if ($svm && $svm->{source} && $svm->{uuid} && $svm->{replace}) {
+		$self->{svm} = $svm;
+	}
+	$self->{svm};
+}
+
+sub _set_svm_vars {
+	my ($self, $ra) = @_;
+	return $ra if $self->svm;
+
+	my @err = ( "useSvmProps set, but failed to read SVM properties\n",
+		    "(svm:source, svm:uuid) ",
+		    "from the following URLs:\n" );
+	sub read_svm_props {
+		my ($self, $ra, $path, $r) = @_;
+		my $props = ($ra->get_dir($path, $r))[2];
+		my $src = $props->{'svm:source'};
+		my $uuid = $props->{'svm:uuid'};
+		return undef if (!$src || !$uuid);
+
+		chomp($src, $uuid);
+
+		$uuid =~ m{^[0-9a-f\-]{30,}$}i
+		    or die "doesn't look right - svm:uuid is '$uuid'\n";
+
+		# the '!' is used to mark the repos_root!/relative/path
+		$src =~ s{/?!/?}{/};
+		$src =~ s{/+$}{}; # no trailing slashes please
+		# username is of no interest
+		$src =~ s{(^[a-z\+]*://)[^/@]*@}{$1};
+
+		my $replace = $ra->{url};
+		$replace .= "/$path" if length $path;
+
+		my $section = "svn-remote.$self->{repo_id}";
+		tmp_config("$section.svm-source", $src);
+		tmp_config("$section.svm-replace", $replace);
+		tmp_config("$section.svm-uuid", $uuid);
+		$self->{svm} = {
+			source => $src,
+			uuid => $uuid,
+			replace => $replace
+		};
+	}
+
+	my $r = $ra->get_latest_revnum;
+	my $path = $self->{path};
+	my %tried;
+	while (length $path) {
+		unless ($tried{"$self->{url}/$path"}) {
+			return $ra if $self->read_svm_props($ra, $path, $r);
+			$tried{"$self->{url}/$path"} = 1;
+		}
+		$path =~ s#/?[^/]+$##;
+	}
+	die "Path: '$path' should be ''\n" if $path ne '';
+	return $ra if $self->read_svm_props($ra, $path, $r);
+	$tried{"$self->{url}/$path"} = 1;
+
+	if ($ra->{repos_root} eq $self->{url}) {
+		die @err, (map { "  $_\n" } keys %tried), "\n";
+	}
+
+	# nope, make sure we're connected to the repository root:
+	my $ok;
+	my @tried_b;
+	$path = $ra->{svn_path};
+	$ra = Git::SVN::Ra->new($ra->{repos_root});
+	while (length $path) {
+		unless ($tried{"$ra->{url}/$path"}) {
+			$ok = $self->read_svm_props($ra, $path, $r);
+			last if $ok;
+			$tried{"$ra->{url}/$path"} = 1;
+		}
+		$path =~ s#/?[^/]+$##;
+	}
+	die "Path: '$path' should be ''\n" if $path ne '';
+	$ok ||= $self->read_svm_props($ra, $path, $r);
+	$tried{"$ra->{url}/$path"} = 1;
+	if (!$ok) {
+		die @err, (map { "  $_\n" } keys %tried), "\n";
+	}
+	Git::SVN::Ra->new($self->{url});
+}
+
+sub svnsync {
+	my ($self) = @_;
+	return $self->{svnsync} if $self->{svnsync};
+
+	if ($self->no_metadata) {
+		die "Can't have both 'noMetadata' and ",
+		    "'useSvnsyncProps' options set!\n";
+	}
+	if ($self->rewrite_root) {
+		die "Can't have both 'useSvnsyncProps' and 'rewriteRoot' ",
+		    "options set!\n";
+	}
+	if ($self->rewrite_uuid) {
+		die "Can't have both 'useSvnsyncProps' and 'rewriteUUID' ",
+		    "options set!\n";
+	}
+
+	my $svnsync;
+	# see if we have it in our config, first:
+	eval {
+		my $section = "svn-remote.$self->{repo_id}";
+
+		my $url = tmp_config('--get', "$section.svnsync-url");
+		($url) = ($url =~ m{^([a-z\+]+://\S+)$}) or
+		   die "doesn't look right - svn:sync-from-url is '$url'\n";
+
+		my $uuid = tmp_config('--get', "$section.svnsync-uuid");
+		($uuid) = ($uuid =~ m{^([0-9a-f\-]{30,})$}i) or
+		   die "doesn't look right - svn:sync-from-uuid is '$uuid'\n";
+
+		$svnsync = { url => $url, uuid => $uuid }
+	};
+	if ($svnsync && $svnsync->{url} && $svnsync->{uuid}) {
+		return $self->{svnsync} = $svnsync;
+	}
+
+	my $err = "useSvnsyncProps set, but failed to read " .
+	          "svnsync property: svn:sync-from-";
+	my $rp = $self->ra->rev_proplist(0);
+
+	my $url = $rp->{'svn:sync-from-url'} or die $err . "url\n";
+	($url) = ($url =~ m{^([a-z\+]+://\S+)$}) or
+	           die "doesn't look right - svn:sync-from-url is '$url'\n";
+
+	my $uuid = $rp->{'svn:sync-from-uuid'} or die $err . "uuid\n";
+	($uuid) = ($uuid =~ m{^([0-9a-f\-]{30,})$}i) or
+	           die "doesn't look right - svn:sync-from-uuid is '$uuid'\n";
+
+	my $section = "svn-remote.$self->{repo_id}";
+	tmp_config('--add', "$section.svnsync-uuid", $uuid);
+	tmp_config('--add', "$section.svnsync-url", $url);
+	return $self->{svnsync} = { url => $url, uuid => $uuid };
+}
+
+# this allows us to memoize our SVN::Ra UUID locally and avoid a
+# remote lookup (useful for 'git svn log').
+sub ra_uuid {
+	my ($self) = @_;
+	unless ($self->{ra_uuid}) {
+		my $key = "svn-remote.$self->{repo_id}.uuid";
+		my $uuid = eval { tmp_config('--get', $key) };
+		if (!$@ && $uuid && $uuid =~ /^([a-f\d\-]{30,})$/i) {
+			$self->{ra_uuid} = $uuid;
+		} else {
+			die "ra_uuid called without URL\n" unless $self->{url};
+			$self->{ra_uuid} = $self->ra->get_uuid;
+			tmp_config('--add', $key, $self->{ra_uuid});
+		}
+	}
+	$self->{ra_uuid};
+}
+
+sub _set_repos_root {
+	my ($self, $repos_root) = @_;
+	my $k = "svn-remote.$self->{repo_id}.reposRoot";
+	$repos_root ||= $self->ra->{repos_root};
+	tmp_config($k, $repos_root);
+	$repos_root;
+}
+
+sub repos_root {
+	my ($self) = @_;
+	my $k = "svn-remote.$self->{repo_id}.reposRoot";
+	eval { tmp_config('--get', $k) } || $self->_set_repos_root;
+}
+
+sub ra {
+	my ($self) = shift;
+	my $ra = Git::SVN::Ra->new($self->{url});
+	$self->_set_repos_root($ra->{repos_root});
+	if ($self->use_svm_props && !$self->{svm}) {
+		if ($self->no_metadata) {
+			die "Can't have both 'noMetadata' and ",
+			    "'useSvmProps' options set!\n";
+		} elsif ($self->use_svnsync_props) {
+			die "Can't have both 'useSvnsyncProps' and ",
+			    "'useSvmProps' options set!\n";
+		}
+		$ra = $self->_set_svm_vars($ra);
+		$self->{-want_revprops} = 1;
+	}
+	$ra;
+}
+
+# prop_walk(PATH, REV, SUB)
+# -------------------------
+# Recursively traverse PATH at revision REV and invoke SUB for each
+# directory that contains a SVN property.  SUB will be invoked as
+# follows:  &SUB(gs, path, props);  where `gs' is this instance of
+# Git::SVN, `path' the path to the directory where the properties
+# `props' were found.  The `path' will be relative to point of checkout,
+# that is, if url://repo/trunk is the current Git branch, and that
+# directory contains a sub-directory `d', SUB will be invoked with `/d/'
+# as `path' (note the trailing `/').
+sub prop_walk {
+	my ($self, $path, $rev, $sub) = @_;
+
+	$path =~ s#^/##;
+	my ($dirent, undef, $props) = $self->ra->get_dir($path, $rev);
+	$path =~ s#^/*#/#g;
+	my $p = $path;
+	# Strip the irrelevant part of the path.
+	$p =~ s#^/+\Q$self->{path}\E(/|$)#/#;
+	# Ensure the path is terminated by a `/'.
+	$p =~ s#/*$#/#;
+
+	# The properties contain all the internal SVN stuff nobody
+	# (usually) cares about.
+	my $interesting_props = 0;
+	foreach (keys %{$props}) {
+		# If it doesn't start with `svn:', it must be a
+		# user-defined property.
+		++$interesting_props and next if $_ !~ /^svn:/;
+		# FIXME: Fragile, if SVN adds new public properties,
+		# this needs to be updated.
+		++$interesting_props if /^svn:(?:ignore|keywords|executable
+		                                 |eol-style|mime-type
+						 |externals|needs-lock)$/x;
+	}
+	&$sub($self, $p, $props) if $interesting_props;
+
+	foreach (sort keys %$dirent) {
+		next if $dirent->{$_}->{kind} != $SVN::Node::dir;
+		$self->prop_walk($self->{path} . $p . $_, $rev, $sub);
+	}
+}
+
+sub last_rev { ($_[0]->last_rev_commit)[0] }
+sub last_commit { ($_[0]->last_rev_commit)[1] }
+
+# returns the newest SVN revision number and newest commit SHA1
+sub last_rev_commit {
+	my ($self) = @_;
+	if (defined $self->{last_rev} && defined $self->{last_commit}) {
+		return ($self->{last_rev}, $self->{last_commit});
+	}
+	my $c = ::verify_ref($self->refname.'^0');
+	if ($c && !$self->use_svm_props && !$self->no_metadata) {
+		my $rev = (::cmt_metadata($c))[1];
+		if (defined $rev) {
+			($self->{last_rev}, $self->{last_commit}) = ($rev, $c);
+			return ($rev, $c);
+		}
+	}
+	my $map_path = $self->map_path;
+	unless (-e $map_path) {
+		($self->{last_rev}, $self->{last_commit}) = (undef, undef);
+		return (undef, undef);
+	}
+	my ($rev, $commit) = $self->rev_map_max(1);
+	($self->{last_rev}, $self->{last_commit}) = ($rev, $commit);
+	return ($rev, $commit);
+}
+
+sub get_fetch_range {
+	my ($self, $min, $max) = @_;
+	$max ||= $self->ra->get_latest_revnum;
+	$min ||= $self->rev_map_max;
+	(++$min, $max);
+}
+
+sub tmp_config {
+	my (@args) = @_;
+	my $old_def_config = "$ENV{GIT_DIR}/svn/config";
+	my $config = "$ENV{GIT_DIR}/svn/.metadata";
+	if (! -f $config && -f $old_def_config) {
+		rename $old_def_config, $config or
+		       die "Failed rename $old_def_config => $config: $!\n";
+	}
+	my $old_config = $ENV{GIT_CONFIG};
+	$ENV{GIT_CONFIG} = $config;
+	$@ = undef;
+	my @ret = eval {
+		unless (-f $config) {
+			mkfile($config);
+			open my $fh, '>', $config or
+			    die "Can't open $config: $!\n";
+			print $fh "; This file is used internally by ",
+			          "git-svn\n" or die
+				  "Couldn't write to $config: $!\n";
+			print $fh "; You should not have to edit it\n" or
+			      die "Couldn't write to $config: $!\n";
+			close $fh or die "Couldn't close $config: $!\n";
+		}
+		command('config', @args);
+	};
+	my $err = $@;
+	if (defined $old_config) {
+		$ENV{GIT_CONFIG} = $old_config;
+	} else {
+		delete $ENV{GIT_CONFIG};
+	}
+	die $err if $err;
+	wantarray ? @ret : $ret[0];
+}
+
+sub tmp_index_do {
+	my ($self, $sub) = @_;
+	my $old_index = $ENV{GIT_INDEX_FILE};
+	$ENV{GIT_INDEX_FILE} = $self->{index};
+	$@ = undef;
+	my @ret = eval {
+		my ($dir, $base) = ($self->{index} =~ m#^(.*?)/?([^/]+)$#);
+		mkpath([$dir]) unless -d $dir;
+		&$sub;
+	};
+	my $err = $@;
+	if (defined $old_index) {
+		$ENV{GIT_INDEX_FILE} = $old_index;
+	} else {
+		delete $ENV{GIT_INDEX_FILE};
+	}
+	die $err if $err;
+	wantarray ? @ret : $ret[0];
+}
+
+sub assert_index_clean {
+	my ($self, $treeish) = @_;
+
+	$self->tmp_index_do(sub {
+		command_noisy('read-tree', $treeish) unless -e $self->{index};
+		my $x = command_oneline('write-tree');
+		my ($y) = (command(qw/cat-file commit/, $treeish) =~
+		           /^tree ($::sha1)/mo);
+		return if $y eq $x;
+
+		warn "Index mismatch: $y != $x\nrereading $treeish\n";
+		unlink $self->{index} or die "unlink $self->{index}: $!\n";
+		command_noisy('read-tree', $treeish);
+		$x = command_oneline('write-tree');
+		if ($y ne $x) {
+			fatal "trees ($treeish) $y != $x\n",
+			      "Something is seriously wrong...";
+		}
+	});
+}
+
+sub get_commit_parents {
+	my ($self, $log_entry) = @_;
+	my (%seen, @ret, @tmp);
+	# legacy support for 'set-tree'; this is only used by set_tree_cb:
+	if (my $ip = $self->{inject_parents}) {
+		if (my $commit = delete $ip->{$log_entry->{revision}}) {
+			push @tmp, $commit;
+		}
+	}
+	if (my $cur = ::verify_ref($self->refname.'^0')) {
+		push @tmp, $cur;
+	}
+	if (my $ipd = $self->{inject_parents_dcommit}) {
+		if (my $commit = delete $ipd->{$log_entry->{revision}}) {
+			push @tmp, @$commit;
+		}
+	}
+	push @tmp, $_ foreach (@{$log_entry->{parents}}, @tmp);
+	while (my $p = shift @tmp) {
+		next if $seen{$p};
+		$seen{$p} = 1;
+		push @ret, $p;
+	}
+	@ret;
+}
+
+sub rewrite_root {
+	my ($self) = @_;
+	return $self->{-rewrite_root} if exists $self->{-rewrite_root};
+	my $k = "svn-remote.$self->{repo_id}.rewriteRoot";
+	my $rwr = eval { command_oneline(qw/config --get/, $k) };
+	if ($rwr) {
+		$rwr =~ s#/+$##;
+		if ($rwr !~ m#^[a-z\+]+://#) {
+			die "$rwr is not a valid URL (key: $k)\n";
+		}
+	}
+	$self->{-rewrite_root} = $rwr;
+}
+
+sub rewrite_uuid {
+	my ($self) = @_;
+	return $self->{-rewrite_uuid} if exists $self->{-rewrite_uuid};
+	my $k = "svn-remote.$self->{repo_id}.rewriteUUID";
+	my $rwid = eval { command_oneline(qw/config --get/, $k) };
+	if ($rwid) {
+		$rwid =~ s#/+$##;
+		if ($rwid !~ m#^[a-f0-9]{8}-(?:[a-f0-9]{4}-){3}[a-f0-9]{12}$#) {
+			die "$rwid is not a valid UUID (key: $k)\n";
+		}
+	}
+	$self->{-rewrite_uuid} = $rwid;
+}
+
+sub metadata_url {
+	my ($self) = @_;
+	($self->rewrite_root || $self->{url}) .
+	   (length $self->{path} ? '/' . $self->{path} : '');
+}
+
+sub full_url {
+	my ($self) = @_;
+	$self->{url} . (length $self->{path} ? '/' . $self->{path} : '');
+}
+
+sub full_pushurl {
+	my ($self) = @_;
+	if ($self->{pushurl}) {
+		return $self->{pushurl} . (length $self->{path} ? '/' .
+		       $self->{path} : '');
+	} else {
+		return $self->full_url;
+	}
+}
+
+sub set_commit_header_env {
+	my ($log_entry) = @_;
+	my %env;
+	foreach my $ned (qw/NAME EMAIL DATE/) {
+		foreach my $ac (qw/AUTHOR COMMITTER/) {
+			$env{"GIT_${ac}_${ned}"} = $ENV{"GIT_${ac}_${ned}"};
+		}
+	}
+
+	$ENV{GIT_AUTHOR_NAME} = $log_entry->{name};
+	$ENV{GIT_AUTHOR_EMAIL} = $log_entry->{email};
+	$ENV{GIT_AUTHOR_DATE} = $ENV{GIT_COMMITTER_DATE} = $log_entry->{date};
+
+	$ENV{GIT_COMMITTER_NAME} = (defined $log_entry->{commit_name})
+						? $log_entry->{commit_name}
+						: $log_entry->{name};
+	$ENV{GIT_COMMITTER_EMAIL} = (defined $log_entry->{commit_email})
+						? $log_entry->{commit_email}
+						: $log_entry->{email};
+	\%env;
+}
+
+sub restore_commit_header_env {
+	my ($env) = @_;
+	foreach my $ned (qw/NAME EMAIL DATE/) {
+		foreach my $ac (qw/AUTHOR COMMITTER/) {
+			my $k = "GIT_${ac}_${ned}";
+			if (defined $env->{$k}) {
+				$ENV{$k} = $env->{$k};
+			} else {
+				delete $ENV{$k};
+			}
+		}
+	}
+}
+
+sub gc {
+	command_noisy('gc', '--auto');
+};
+
+sub do_git_commit {
+	my ($self, $log_entry) = @_;
+	my $lr = $self->last_rev;
+	if (defined $lr && $lr >= $log_entry->{revision}) {
+		die "Last fetched revision of ", $self->refname,
+		    " was r$lr, but we are about to fetch: ",
+		    "r$log_entry->{revision}!\n";
+	}
+	if (my $c = $self->rev_map_get($log_entry->{revision})) {
+		croak "$log_entry->{revision} = $c already exists! ",
+		      "Why are we refetching it?\n";
+	}
+	my $old_env = set_commit_header_env($log_entry);
+	my $tree = $log_entry->{tree};
+	if (!defined $tree) {
+		$tree = $self->tmp_index_do(sub {
+		                            command_oneline('write-tree') });
+	}
+	die "Tree is not a valid sha1: $tree\n" if $tree !~ /^$::sha1$/o;
+
+	my @exec = ('git', 'commit-tree', $tree);
+	foreach ($self->get_commit_parents($log_entry)) {
+		push @exec, '-p', $_;
+	}
+	defined(my $pid = open3(my $msg_fh, my $out_fh, '>&STDERR', @exec))
+	                                                           or croak $!;
+	binmode $msg_fh;
+
+	# we always get UTF-8 from SVN, but we may want our commits in
+	# a different encoding.
+	if (my $enc = Git::config('i18n.commitencoding')) {
+		require Encode;
+		Encode::from_to($log_entry->{log}, 'UTF-8', $enc);
+	}
+	print $msg_fh $log_entry->{log} or croak $!;
+	restore_commit_header_env($old_env);
+	unless ($self->no_metadata) {
+		print $msg_fh "\ngit-svn-id: $log_entry->{metadata}\n"
+		              or croak $!;
+	}
+	$msg_fh->flush == 0 or croak $!;
+	close $msg_fh or croak $!;
+	chomp(my $commit = do { local $/; <$out_fh> });
+	close $out_fh or croak $!;
+	waitpid $pid, 0;
+	croak $? if $?;
+	if ($commit !~ /^$::sha1$/o) {
+		die "Failed to commit, invalid sha1: $commit\n";
+	}
+
+	$self->rev_map_set($log_entry->{revision}, $commit, 1);
+
+	$self->{last_rev} = $log_entry->{revision};
+	$self->{last_commit} = $commit;
+	print "r$log_entry->{revision}" unless $::_q > 1;
+	if (defined $log_entry->{svm_revision}) {
+		 print " (\@$log_entry->{svm_revision})" unless $::_q > 1;
+		 $self->rev_map_set($log_entry->{svm_revision}, $commit,
+		                   0, $self->svm_uuid);
+	}
+	print " = $commit ($self->{ref_id})\n" unless $::_q > 1;
+	if (--$_gc_nr == 0) {
+		$_gc_nr = $_gc_period;
+		gc();
+	}
+	return $commit;
+}
+
+sub match_paths {
+	my ($self, $paths, $r) = @_;
+	return 1 if $self->{path} eq '';
+	if (my $path = $paths->{"/$self->{path}"}) {
+		return ($path->{action} eq 'D') ? 0 : 1;
+	}
+	$self->{path_regex} ||= qr/^\/\Q$self->{path}\E\//;
+	if (grep /$self->{path_regex}/, keys %$paths) {
+		return 1;
+	}
+	my $c = '';
+	foreach (split m#/#, $self->{path}) {
+		$c .= "/$_";
+		next unless ($paths->{$c} &&
+		             ($paths->{$c}->{action} =~ /^[AR]$/));
+		if ($self->ra->check_path($self->{path}, $r) ==
+		    $SVN::Node::dir) {
+			return 1;
+		}
+	}
+	return 0;
+}
+
+sub find_parent_branch {
+	my ($self, $paths, $rev) = @_;
+	return undef unless $self->follow_parent;
+	unless (defined $paths) {
+		my $err_handler = $SVN::Error::handler;
+		$SVN::Error::handler = \&Git::SVN::Ra::skip_unknown_revs;
+		$self->ra->get_log([$self->{path}], $rev, $rev, 0, 1, 1,
+				   sub { $paths = $_[0] });
+		$SVN::Error::handler = $err_handler;
+	}
+	return undef unless defined $paths;
+
+	# look for a parent from another branch:
+	my @b_path_components = split m#/#, $self->{path};
+	my @a_path_components;
+	my $i;
+	while (@b_path_components) {
+		$i = $paths->{'/'.join('/', @b_path_components)};
+		last if $i && defined $i->{copyfrom_path};
+		unshift(@a_path_components, pop(@b_path_components));
+	}
+	return undef unless defined $i && defined $i->{copyfrom_path};
+	my $branch_from = $i->{copyfrom_path};
+	if (@a_path_components) {
+		print STDERR "branch_from: $branch_from => ";
+		$branch_from .= '/'.join('/', @a_path_components);
+		print STDERR $branch_from, "\n";
+	}
+	my $r = $i->{copyfrom_rev};
+	my $repos_root = $self->ra->{repos_root};
+	my $url = $self->ra->{url};
+	my $new_url = $url . $branch_from;
+	print STDERR  "Found possible branch point: ",
+	              "$new_url => ", $self->full_url, ", $r\n"
+	              unless $::_q > 1;
+	$branch_from =~ s#^/##;
+	my $gs = $self->other_gs($new_url, $url,
+		                 $branch_from, $r, $self->{ref_id});
+	my ($r0, $parent) = $gs->find_rev_before($r, 1);
+	{
+		my ($base, $head);
+		if (!defined $r0 || !defined $parent) {
+			($base, $head) = parse_revision_argument(0, $r);
+		} else {
+			if ($r0 < $r) {
+				$gs->ra->get_log([$gs->{path}], $r0 + 1, $r, 1,
+					0, 1, sub { $base = $_[1] - 1 });
+			}
+		}
+		if (defined $base && $base <= $r) {
+			$gs->fetch($base, $r);
+		}
+		($r0, $parent) = $gs->find_rev_before($r, 1);
+	}
+	if (defined $r0 && defined $parent) {
+		print STDERR "Found branch parent: ($self->{ref_id}) $parent\n"
+		             unless $::_q > 1;
+		my $ed;
+		if ($self->ra->can_do_switch) {
+			$self->assert_index_clean($parent);
+			print STDERR "Following parent with do_switch\n"
+			             unless $::_q > 1;
+			# do_switch works with svn/trunk >= r22312, but that
+			# is not included with SVN 1.4.3 (the latest version
+			# at the moment), so we can't rely on it
+			$self->{last_rev} = $r0;
+			$self->{last_commit} = $parent;
+			$ed = Git::SVN::Fetcher->new($self, $gs->{path});
+			$gs->ra->gs_do_switch($r0, $rev, $gs,
+					      $self->full_url, $ed)
+			  or die "SVN connection failed somewhere...\n";
+		} elsif ($self->ra->trees_match($new_url, $r0,
+			                        $self->full_url, $rev)) {
+			print STDERR "Trees match:\n",
+			             "  $new_url\@$r0\n",
+			             "  ${\$self->full_url}\@$rev\n",
+			             "Following parent with no changes\n"
+			             unless $::_q > 1;
+			$self->tmp_index_do(sub {
+			    command_noisy('read-tree', $parent);
+			});
+			$self->{last_commit} = $parent;
+		} else {
+			print STDERR "Following parent with do_update\n"
+			             unless $::_q > 1;
+			$ed = Git::SVN::Fetcher->new($self);
+			$self->ra->gs_do_update($rev, $rev, $self, $ed)
+			  or die "SVN connection failed somewhere...\n";
+		}
+		print STDERR "Successfully followed parent\n" unless $::_q > 1;
+		return $self->make_log_entry($rev, [$parent], $ed);
+	}
+	return undef;
+}
+
+sub do_fetch {
+	my ($self, $paths, $rev) = @_;
+	my $ed;
+	my ($last_rev, @parents);
+	if (my $lc = $self->last_commit) {
+		# we can have a branch that was deleted, then re-added
+		# under the same name but copied from another path, in
+		# which case we'll have multiple parents (we don't
+		# want to break the original ref, nor lose copypath info):
+		if (my $log_entry = $self->find_parent_branch($paths, $rev)) {
+			push @{$log_entry->{parents}}, $lc;
+			return $log_entry;
+		}
+		$ed = Git::SVN::Fetcher->new($self);
+		$last_rev = $self->{last_rev};
+		$ed->{c} = $lc;
+		@parents = ($lc);
+	} else {
+		$last_rev = $rev;
+		if (my $log_entry = $self->find_parent_branch($paths, $rev)) {
+			return $log_entry;
+		}
+		$ed = Git::SVN::Fetcher->new($self);
+	}
+	unless ($self->ra->gs_do_update($last_rev, $rev, $self, $ed)) {
+		die "SVN connection failed somewhere...\n";
+	}
+	$self->make_log_entry($rev, \@parents, $ed);
+}
+
+sub mkemptydirs {
+	my ($self, $r) = @_;
+
+	sub scan {
+		my ($r, $empty_dirs, $line) = @_;
+		if (defined $r && $line =~ /^r(\d+)$/) {
+			return 0 if $1 > $r;
+		} elsif ($line =~ /^  \+empty_dir: (.+)$/) {
+			$empty_dirs->{$1} = 1;
+		} elsif ($line =~ /^  \-empty_dir: (.+)$/) {
+			my @d = grep {m[^\Q$1\E(/|$)]} (keys %$empty_dirs);
+			delete @$empty_dirs{@d};
+		}
+		1; # continue
+	};
+
+	my %empty_dirs = ();
+	my $gz_file = "$self->{dir}/unhandled.log.gz";
+	if (-f $gz_file) {
+		if (!can_compress()) {
+			warn "Compress::Zlib could not be found; ",
+			     "empty directories in $gz_file will not be read\n";
+		} else {
+			my $gz = Compress::Zlib::gzopen($gz_file, "rb") or
+				die "Unable to open $gz_file: $!\n";
+			my $line;
+			while ($gz->gzreadline($line) > 0) {
+				scan($r, \%empty_dirs, $line) or last;
+			}
+			$gz->gzclose;
+		}
+	}
+
+	if (open my $fh, '<', "$self->{dir}/unhandled.log") {
+		binmode $fh or croak "binmode: $!";
+		while (<$fh>) {
+			scan($r, \%empty_dirs, $_) or last;
+		}
+		close $fh;
+	}
+
+	my $strip = qr/\A\Q$self->{path}\E(?:\/|$)/;
+	foreach my $d (sort keys %empty_dirs) {
+		$d = uri_decode($d);
+		$d =~ s/$strip//;
+		next unless length($d);
+		next if -d $d;
+		if (-e $d) {
+			warn "$d exists but is not a directory\n";
+		} else {
+			print "creating empty directory: $d\n";
+			mkpath([$d]);
+		}
+	}
+}
+
+sub get_untracked {
+	my ($self, $ed) = @_;
+	my @out;
+	my $h = $ed->{empty};
+	foreach (sort keys %$h) {
+		my $act = $h->{$_} ? '+empty_dir' : '-empty_dir';
+		push @out, "  $act: " . uri_encode($_);
+		warn "W: $act: $_\n";
+	}
+	foreach my $t (qw/dir_prop file_prop/) {
+		$h = $ed->{$t} or next;
+		foreach my $path (sort keys %$h) {
+			my $ppath = $path eq '' ? '.' : $path;
+			foreach my $prop (sort keys %{$h->{$path}}) {
+				next if $SKIP_PROP{$prop};
+				my $v = $h->{$path}->{$prop};
+				my $t_ppath_prop = "$t: " .
+				                    uri_encode($ppath) . ' ' .
+				                    uri_encode($prop);
+				if (defined $v) {
+					push @out, "  +$t_ppath_prop " .
+					           uri_encode($v);
+				} else {
+					push @out, "  -$t_ppath_prop";
+				}
+			}
+		}
+	}
+	foreach my $t (qw/absent_file absent_directory/) {
+		$h = $ed->{$t} or next;
+		foreach my $parent (sort keys %$h) {
+			foreach my $path (sort @{$h->{$parent}}) {
+				push @out, "  $t: " .
+				           uri_encode("$parent/$path");
+				warn "W: $t: $parent/$path ",
+				     "Insufficient permissions?\n";
+			}
+		}
+	}
+	\@out;
+}
+
+sub get_tz {
+	# some systmes don't handle or mishandle %z, so be creative.
+	my $t = shift || time;
+	my $gm = timelocal(gmtime($t));
+	my $sign = qw( + + - )[ $t <=> $gm ];
+	return sprintf("%s%02d%02d", $sign, (gmtime(abs($t - $gm)))[2,1]);
+}
+
+# parse_svn_date(DATE)
+# --------------------
+# Given a date (in UTC) from Subversion, return a string in the format
+# "<TZ Offset> <local date/time>" that Git will use.
+#
+# By default the parsed date will be in UTC; if $Git::SVN::_localtime
+# is true we'll convert it to the local timezone instead.
+sub parse_svn_date {
+	my $date = shift || return '+0000 1970-01-01 00:00:00';
+	my ($Y,$m,$d,$H,$M,$S) = ($date =~ /^(\d{4})\-(\d\d)\-(\d\d)T
+	                                    (\d\d)\:(\d\d)\:(\d\d)\.\d*Z$/x) or
+	                                 croak "Unable to parse date: $date\n";
+	my $parsed_date;    # Set next.
+
+	if ($Git::SVN::_localtime) {
+		# Translate the Subversion datetime to an epoch time.
+		# Begin by switching ourselves to $date's timezone, UTC.
+		my $old_env_TZ = $ENV{TZ};
+		$ENV{TZ} = 'UTC';
+
+		my $epoch_in_UTC =
+		    POSIX::strftime('%s', $S, $M, $H, $d, $m - 1, $Y - 1900);
+
+		# Determine our local timezone (including DST) at the
+		# time of $epoch_in_UTC.  $Git::SVN::Log::TZ stored the
+		# value of TZ, if any, at the time we were run.
+		if (defined $Git::SVN::Log::TZ) {
+			$ENV{TZ} = $Git::SVN::Log::TZ;
+		} else {
+			delete $ENV{TZ};
+		}
+
+		my $our_TZ = get_tz();
+
+		# This converts $epoch_in_UTC into our local timezone.
+		my ($sec, $min, $hour, $mday, $mon, $year,
+		    $wday, $yday, $isdst) = localtime($epoch_in_UTC);
+
+		$parsed_date = sprintf('%s %04d-%02d-%02d %02d:%02d:%02d',
+				       $our_TZ, $year + 1900, $mon + 1,
+				       $mday, $hour, $min, $sec);
+
+		# Reset us to the timezone in effect when we entered
+		# this routine.
+		if (defined $old_env_TZ) {
+			$ENV{TZ} = $old_env_TZ;
+		} else {
+			delete $ENV{TZ};
+		}
+	} else {
+		$parsed_date = "+0000 $Y-$m-$d $H:$M:$S";
+	}
+
+	return $parsed_date;
+}
+
+sub other_gs {
+	my ($self, $new_url, $url,
+	    $branch_from, $r, $old_ref_id) = @_;
+	my $gs = Git::SVN->find_by_url($new_url, $url, $branch_from);
+	unless ($gs) {
+		my $ref_id = $old_ref_id;
+		$ref_id =~ s/\@\d+-*$//;
+		$ref_id .= "\@$r";
+		# just grow a tail if we're not unique enough :x
+		$ref_id .= '-' while find_ref($ref_id);
+		my ($u, $p, $repo_id) = ($new_url, '', $ref_id);
+		if ($u =~ s#^\Q$url\E(/|$)##) {
+			$p = $u;
+			$u = $url;
+			$repo_id = $self->{repo_id};
+		}
+		while (1) {
+			# It is possible to tag two different subdirectories at
+			# the same revision.  If the url for an existing ref
+			# does not match, we must either find a ref with a
+			# matching url or create a new ref by growing a tail.
+			$gs = Git::SVN->init($u, $p, $repo_id, $ref_id, 1);
+			my (undef, $max_commit) = $gs->rev_map_max(1);
+			last if (!$max_commit);
+			my ($url) = ::cmt_metadata($max_commit);
+			last if ($url eq $gs->metadata_url);
+			$ref_id .= '-';
+		}
+		print STDERR "Initializing parent: $ref_id\n" unless $::_q > 1;
+	}
+	$gs
+}
+
+sub call_authors_prog {
+	my ($orig_author) = @_;
+	$orig_author = command_oneline('rev-parse', '--sq-quote', $orig_author);
+	my $author = `$::_authors_prog $orig_author`;
+	if ($? != 0) {
+		die "$::_authors_prog failed with exit code $?\n"
+	}
+	if ($author =~ /^\s*(.+?)\s*<(.*)>\s*$/) {
+		my ($name, $email) = ($1, $2);
+		$email = undef if length $2 == 0;
+		return [$name, $email];
+	} else {
+		die "Author: $orig_author: $::_authors_prog returned "
+			. "invalid author format: $author\n";
+	}
+}
+
+sub check_author {
+	my ($author) = @_;
+	if (!defined $author || length $author == 0) {
+		$author = '(no author)';
+	}
+	if (!defined $::users{$author}) {
+		if (defined $::_authors_prog) {
+			$::users{$author} = call_authors_prog($author);
+		} elsif (defined $::_authors) {
+			die "Author: $author not defined in $::_authors file\n";
+		}
+	}
+	$author;
+}
+
+sub find_extra_svk_parents {
+	my ($self, $ed, $tickets, $parents) = @_;
+	# aha!  svk:merge property changed...
+	my @tickets = split "\n", $tickets;
+	my @known_parents;
+	for my $ticket ( @tickets ) {
+		my ($uuid, $path, $rev) = split /:/, $ticket;
+		if ( $uuid eq $self->ra_uuid ) {
+			my $url = $self->{url};
+			my $repos_root = $url;
+			my $branch_from = $path;
+			$branch_from =~ s{^/}{};
+			my $gs = $self->other_gs($repos_root."/".$branch_from,
+			                         $url,
+			                         $branch_from,
+			                         $rev,
+			                         $self->{ref_id});
+			if ( my $commit = $gs->rev_map_get($rev, $uuid) ) {
+				# wahey!  we found it, but it might be
+				# an old one (!)
+				push @known_parents, [ $rev, $commit ];
+			}
+		}
+	}
+	# Ordering matters; highest-numbered commit merge tickets
+	# first, as they may account for later merge ticket additions
+	# or changes.
+	@known_parents = map {$_->[1]} sort {$b->[0] <=> $a->[0]} @known_parents;
+	for my $parent ( @known_parents ) {
+		my @cmd = ('rev-list', $parent, map { "^$_" } @$parents );
+		my ($msg_fh, $ctx) = command_output_pipe(@cmd);
+		my $new;
+		while ( <$msg_fh> ) {
+			$new=1;last;
+		}
+		command_close_pipe($msg_fh, $ctx);
+		if ( $new ) {
+			print STDERR
+			    "Found merge parent (svk:merge ticket): $parent\n";
+			push @$parents, $parent;
+		}
+	}
+}
+
+sub lookup_svn_merge {
+	my $uuid = shift;
+	my $url = shift;
+	my $merge = shift;
+
+	my ($source, $revs) = split ":", $merge;
+	my $path = $source;
+	$path =~ s{^/}{};
+	my $gs = Git::SVN->find_by_url($url.$source, $url, $path);
+	if ( !$gs ) {
+		warn "Couldn't find revmap for $url$source\n";
+		return;
+	}
+	my @ranges = split ",", $revs;
+	my ($tip, $tip_commit);
+	my @merged_commit_ranges;
+	# find the tip
+	for my $range ( @ranges ) {
+		my ($bottom, $top) = split "-", $range;
+		$top ||= $bottom;
+		my $bottom_commit = $gs->find_rev_after( $bottom, 1, $top );
+		my $top_commit = $gs->find_rev_before( $top, 1, $bottom );
+
+		unless ($top_commit and $bottom_commit) {
+			warn "W:unknown path/rev in svn:mergeinfo "
+				."dirprop: $source:$range\n";
+			next;
+		}
+
+		if (scalar(command('rev-parse', "$bottom_commit^@"))) {
+			push @merged_commit_ranges,
+			     "$bottom_commit^..$top_commit";
+		} else {
+			push @merged_commit_ranges, "$top_commit";
+		}
+
+		if ( !defined $tip or $top > $tip ) {
+			$tip = $top;
+			$tip_commit = $top_commit;
+		}
+	}
+	return ($tip_commit, @merged_commit_ranges);
+}
+
+sub _rev_list {
+	my ($msg_fh, $ctx) = command_output_pipe(
+		"rev-list", @_,
+	       );
+	my @rv;
+	while ( <$msg_fh> ) {
+		chomp;
+		push @rv, $_;
+	}
+	command_close_pipe($msg_fh, $ctx);
+	@rv;
+}
+
+sub check_cherry_pick {
+	my $base = shift;
+	my $tip = shift;
+	my $parents = shift;
+	my @ranges = @_;
+	my %commits = map { $_ => 1 }
+		_rev_list("--no-merges", $tip, "--not", $base, @$parents, "--");
+	for my $range ( @ranges ) {
+		delete @commits{_rev_list($range, "--")};
+	}
+	for my $commit (keys %commits) {
+		if (has_no_changes($commit)) {
+			delete $commits{$commit};
+		}
+	}
+	return (keys %commits);
+}
+
+sub has_no_changes {
+	my $commit = shift;
+
+	my @revs = split / /, command_oneline(
+		qw(rev-list --parents -1 -m), $commit);
+
+	# Commits with no parents, e.g. the start of a partial branch,
+	# have changes by definition.
+	return 1 if (@revs < 2);
+
+	# Commits with multiple parents, e.g a merge, have no changes
+	# by definition.
+	return 0 if (@revs > 2);
+
+	return (command_oneline("rev-parse", "$commit^{tree}") eq
+		command_oneline("rev-parse", "$commit~1^{tree}"));
+}
+
+sub tie_for_persistent_memoization {
+	my $hash = shift;
+	my $path = shift;
+
+	if ($can_use_yaml) {
+		tie %$hash => 'Git::SVN::Memoize::YAML', "$path.yaml";
+	} else {
+		tie %$hash => 'Memoize::Storable', "$path.db", 'nstore';
+	}
+}
+
+# The GIT_DIR environment variable is not always set until after the command
+# line arguments are processed, so we can't memoize in a BEGIN block.
+{
+	my $memoized = 0;
+
+	sub memoize_svn_mergeinfo_functions {
+		return if $memoized;
+		$memoized = 1;
+
+		my $cache_path = "$ENV{GIT_DIR}/svn/.caches/";
+		mkpath([$cache_path]) unless -d $cache_path;
+
+		my %lookup_svn_merge_cache;
+		my %check_cherry_pick_cache;
+		my %has_no_changes_cache;
+
+		tie_for_persistent_memoization(\%lookup_svn_merge_cache,
+		    "$cache_path/lookup_svn_merge");
+		memoize 'lookup_svn_merge',
+			SCALAR_CACHE => 'FAULT',
+			LIST_CACHE => ['HASH' => \%lookup_svn_merge_cache],
+		;
+
+		tie_for_persistent_memoization(\%check_cherry_pick_cache,
+		    "$cache_path/check_cherry_pick");
+		memoize 'check_cherry_pick',
+			SCALAR_CACHE => 'FAULT',
+			LIST_CACHE => ['HASH' => \%check_cherry_pick_cache],
+		;
+
+		tie_for_persistent_memoization(\%has_no_changes_cache,
+		    "$cache_path/has_no_changes");
+		memoize 'has_no_changes',
+			SCALAR_CACHE => ['HASH' => \%has_no_changes_cache],
+			LIST_CACHE => 'FAULT',
+		;
+	}
+
+	sub unmemoize_svn_mergeinfo_functions {
+		return if not $memoized;
+		$memoized = 0;
+
+		Memoize::unmemoize 'lookup_svn_merge';
+		Memoize::unmemoize 'check_cherry_pick';
+		Memoize::unmemoize 'has_no_changes';
+	}
+
+	Memoize::memoize 'Git::SVN::repos_root';
+}
+
+END {
+	# Force cache writeout explicitly instead of waiting for
+	# global destruction to avoid segfault in Storable:
+	# http://rt.cpan.org/Public/Bug/Display.html?id=36087
+	unmemoize_svn_mergeinfo_functions();
+}
+
+sub parents_exclude {
+	my $parents = shift;
+	my @commits = @_;
+	return unless @commits;
+
+	my @excluded;
+	my $excluded;
+	do {
+		my @cmd = ('rev-list', "-1", @commits, "--not", @$parents );
+		$excluded = command_oneline(@cmd);
+		if ( $excluded ) {
+			my @new;
+			my $found;
+			for my $commit ( @commits ) {
+				if ( $commit eq $excluded ) {
+					push @excluded, $commit;
+					$found++;
+					last;
+				}
+				else {
+					push @new, $commit;
+				}
+			}
+			die "saw commit '$excluded' in rev-list output, "
+				."but we didn't ask for that commit (wanted: @commits --not @$parents)"
+					unless $found;
+			@commits = @new;
+		}
+	}
+		while ($excluded and @commits);
+
+	return @excluded;
+}
+
+
+# note: this function should only be called if the various dirprops
+# have actually changed
+sub find_extra_svn_parents {
+	my ($self, $ed, $mergeinfo, $parents) = @_;
+	# aha!  svk:merge property changed...
+
+	memoize_svn_mergeinfo_functions();
+
+	# We first search for merged tips which are not in our
+	# history.  Then, we figure out which git revisions are in
+	# that tip, but not this revision.  If all of those revisions
+	# are now marked as merge, we can add the tip as a parent.
+	my @merges = split "\n", $mergeinfo;
+	my @merge_tips;
+	my $url = $self->{url};
+	my $uuid = $self->ra_uuid;
+	my %ranges;
+	for my $merge ( @merges ) {
+		my ($tip_commit, @ranges) =
+			lookup_svn_merge( $uuid, $url, $merge );
+		unless (!$tip_commit or
+				grep { $_ eq $tip_commit } @$parents ) {
+			push @merge_tips, $tip_commit;
+			$ranges{$tip_commit} = \@ranges;
+		} else {
+			push @merge_tips, undef;
+		}
+	}
+
+	my %excluded = map { $_ => 1 }
+		parents_exclude($parents, grep { defined } @merge_tips);
+
+	# check merge tips for new parents
+	my @new_parents;
+	for my $merge_tip ( @merge_tips ) {
+		my $spec = shift @merges;
+		next unless $merge_tip and $excluded{$merge_tip};
+
+		my $ranges = $ranges{$merge_tip};
+
+		# check out 'new' tips
+		my $merge_base;
+		eval {
+			$merge_base = command_oneline(
+				"merge-base",
+				@$parents, $merge_tip,
+			);
+		};
+		if ($@) {
+			die "An error occurred during merge-base"
+				unless $@->isa("Git::Error::Command");
+
+			warn "W: Cannot find common ancestor between ".
+			     "@$parents and $merge_tip. Ignoring merge info.\n";
+			next;
+		}
+
+		# double check that there are no missing non-merge commits
+		my (@incomplete) = check_cherry_pick(
+			$merge_base, $merge_tip,
+			$parents,
+			@$ranges,
+		       );
+
+		if ( @incomplete ) {
+			warn "W:svn cherry-pick ignored ($spec) - missing "
+				.@incomplete." commit(s) (eg $incomplete[0])\n";
+		} else {
+			warn
+				"Found merge parent (svn:mergeinfo prop): ",
+					$merge_tip, "\n";
+			push @new_parents, $merge_tip;
+		}
+	}
+
+	# cater for merges which merge commits from multiple branches
+	if ( @new_parents > 1 ) {
+		for ( my $i = 0; $i <= $#new_parents; $i++ ) {
+			for ( my $j = 0; $j <= $#new_parents; $j++ ) {
+				next if $i == $j;
+				next unless $new_parents[$i];
+				next unless $new_parents[$j];
+				my $revs = command_oneline(
+					"rev-list", "-1",
+					"$new_parents[$i]..$new_parents[$j]",
+				       );
+				if ( !$revs ) {
+					undef($new_parents[$j]);
+				}
+			}
+		}
+	}
+	push @$parents, grep { defined } @new_parents;
+}
+
+sub make_log_entry {
+	my ($self, $rev, $parents, $ed) = @_;
+	my $untracked = $self->get_untracked($ed);
+
+	my @parents = @$parents;
+	my $ps = $ed->{path_strip} || "";
+	for my $path ( grep { m/$ps/ } %{$ed->{dir_prop}} ) {
+		my $props = $ed->{dir_prop}{$path};
+		if ( $props->{"svk:merge"} ) {
+			$self->find_extra_svk_parents
+				($ed, $props->{"svk:merge"}, \@parents);
+		}
+		if ( $props->{"svn:mergeinfo"} ) {
+			$self->find_extra_svn_parents
+				($ed,
+				 $props->{"svn:mergeinfo"},
+				 \@parents);
+		}
+	}
+
+	open my $un, '>>', "$self->{dir}/unhandled.log" or croak $!;
+	print $un "r$rev\n" or croak $!;
+	print $un $_, "\n" foreach @$untracked;
+	my %log_entry = ( parents => \@parents, revision => $rev,
+	                  log => '');
+
+	my $headrev;
+	my $logged = delete $self->{logged_rev_props};
+	if (!$logged || $self->{-want_revprops}) {
+		my $rp = $self->ra->rev_proplist($rev);
+		foreach (sort keys %$rp) {
+			my $v = $rp->{$_};
+			if (/^svn:(author|date|log)$/) {
+				$log_entry{$1} = $v;
+			} elsif ($_ eq 'svm:headrev') {
+				$headrev = $v;
+			} else {
+				print $un "  rev_prop: ", uri_encode($_), ' ',
+					  uri_encode($v), "\n";
+			}
+		}
+	} else {
+		map { $log_entry{$_} = $logged->{$_} } keys %$logged;
+	}
+	close $un or croak $!;
+
+	$log_entry{date} = parse_svn_date($log_entry{date});
+	$log_entry{log} .= "\n";
+	my $author = $log_entry{author} = check_author($log_entry{author});
+	my ($name, $email) = defined $::users{$author} ? @{$::users{$author}}
+						       : ($author, undef);
+
+	my ($commit_name, $commit_email) = ($name, $email);
+	if ($_use_log_author) {
+		my $name_field;
+		if ($log_entry{log} =~ /From:\s+(.*\S)\s*\n/i) {
+			$name_field = $1;
+		} elsif ($log_entry{log} =~ /Signed-off-by:\s+(.*\S)\s*\n/i) {
+			$name_field = $1;
+		}
+		if (!defined $name_field) {
+			if (!defined $email) {
+				$email = $name;
+			}
+		} elsif ($name_field =~ /(.*?)\s+<(.*)>/) {
+			($name, $email) = ($1, $2);
+		} elsif ($name_field =~ /(.*)@/) {
+			($name, $email) = ($1, $name_field);
+		} else {
+			($name, $email) = ($name_field, $name_field);
+		}
+	}
+	if (defined $headrev && $self->use_svm_props) {
+		if ($self->rewrite_root) {
+			die "Can't have both 'useSvmProps' and 'rewriteRoot' ",
+			    "options set!\n";
+		}
+		if ($self->rewrite_uuid) {
+			die "Can't have both 'useSvmProps' and 'rewriteUUID' ",
+			    "options set!\n";
+		}
+		my ($uuid, $r) = $headrev =~ m{^([a-f\d\-]{30,}):(\d+)$}i;
+		# we don't want "SVM: initializing mirror for junk" ...
+		return undef if $r == 0;
+		my $svm = $self->svm;
+		if ($uuid ne $svm->{uuid}) {
+			die "UUID mismatch on SVM path:\n",
+			    "expected: $svm->{uuid}\n",
+			    "     got: $uuid\n";
+		}
+		my $full_url = $self->full_url;
+		$full_url =~ s#^\Q$svm->{replace}\E(/|$)#$svm->{source}$1# or
+		             die "Failed to replace '$svm->{replace}' with ",
+		                 "'$svm->{source}' in $full_url\n";
+		# throw away username for storing in records
+		remove_username($full_url);
+		$log_entry{metadata} = "$full_url\@$r $uuid";
+		$log_entry{svm_revision} = $r;
+		$email ||= "$author\@$uuid";
+		$commit_email ||= "$author\@$uuid";
+	} elsif ($self->use_svnsync_props) {
+		my $full_url = $self->svnsync->{url};
+		$full_url .= "/$self->{path}" if length $self->{path};
+		remove_username($full_url);
+		my $uuid = $self->svnsync->{uuid};
+		$log_entry{metadata} = "$full_url\@$rev $uuid";
+		$email ||= "$author\@$uuid";
+		$commit_email ||= "$author\@$uuid";
+	} else {
+		my $url = $self->metadata_url;
+		remove_username($url);
+		my $uuid = $self->rewrite_uuid || $self->ra->get_uuid;
+		$log_entry{metadata} = "$url\@$rev " . $uuid;
+		$email ||= "$author\@" . $uuid;
+		$commit_email ||= "$author\@" . $uuid;
+	}
+	$log_entry{name} = $name;
+	$log_entry{email} = $email;
+	$log_entry{commit_name} = $commit_name;
+	$log_entry{commit_email} = $commit_email;
+	\%log_entry;
+}
+
+sub fetch {
+	my ($self, $min_rev, $max_rev, @parents) = @_;
+	my ($last_rev, $last_commit) = $self->last_rev_commit;
+	my ($base, $head) = $self->get_fetch_range($min_rev, $max_rev);
+	$self->ra->gs_fetch_loop_common($base, $head, [$self]);
+}
+
+sub set_tree_cb {
+	my ($self, $log_entry, $tree, $rev, $date, $author) = @_;
+	$self->{inject_parents} = { $rev => $tree };
+	$self->fetch(undef, undef);
+}
+
+sub set_tree {
+	my ($self, $tree) = (shift, shift);
+	my $log_entry = ::get_commit_entry($tree);
+	unless ($self->{last_rev}) {
+		fatal("Must have an existing revision to commit");
+	}
+	my %ed_opts = ( r => $self->{last_rev},
+	                log => $log_entry->{log},
+	                ra => $self->ra,
+	                tree_a => $self->{last_commit},
+	                tree_b => $tree,
+	                editor_cb => sub {
+			       $self->set_tree_cb($log_entry, $tree, @_) },
+	                svn_path => $self->{path} );
+	if (!Git::SVN::Editor->new(\%ed_opts)->apply_diff) {
+		print "No changes\nr$self->{last_rev} = $tree\n";
+	}
+}
+
+sub rebuild_from_rev_db {
+	my ($self, $path) = @_;
+	my $r = -1;
+	open my $fh, '<', $path or croak "open: $!";
+	binmode $fh or croak "binmode: $!";
+	while (<$fh>) {
+		length($_) == 41 or croak "inconsistent size in ($_) != 41";
+		chomp($_);
+		++$r;
+		next if $_ eq ('0' x 40);
+		$self->rev_map_set($r, $_);
+		print "r$r = $_\n";
+	}
+	close $fh or croak "close: $!";
+	unlink $path or croak "unlink: $!";
+}
+
+sub rebuild {
+	my ($self) = @_;
+	my $map_path = $self->map_path;
+	my $partial = (-e $map_path && ! -z $map_path);
+	return unless ::verify_ref($self->refname.'^0');
+	if (!$partial && ($self->use_svm_props || $self->no_metadata)) {
+		my $rev_db = $self->rev_db_path;
+		$self->rebuild_from_rev_db($rev_db);
+		if ($self->use_svm_props) {
+			my $svm_rev_db = $self->rev_db_path($self->svm_uuid);
+			$self->rebuild_from_rev_db($svm_rev_db);
+		}
+		$self->unlink_rev_db_symlink;
+		return;
+	}
+	print "Rebuilding $map_path ...\n" if (!$partial);
+	my ($base_rev, $head) = ($partial ? $self->rev_map_max_norebuild(1) :
+		(undef, undef));
+	my ($log, $ctx) =
+	    command_output_pipe(qw/rev-list --pretty=raw --reverse/,
+				($head ? "$head.." : "") . $self->refname,
+				'--');
+	my $metadata_url = $self->metadata_url;
+	remove_username($metadata_url);
+	my $svn_uuid = $self->rewrite_uuid || $self->ra_uuid;
+	my $c;
+	while (<$log>) {
+		if ( m{^commit ($::sha1)$} ) {
+			$c = $1;
+			next;
+		}
+		next unless s{^\s*(git-svn-id:)}{$1};
+		my ($url, $rev, $uuid) = ::extract_metadata($_);
+		remove_username($url);
+
+		# ignore merges (from set-tree)
+		next if (!defined $rev || !$uuid);
+
+		# if we merged or otherwise started elsewhere, this is
+		# how we break out of it
+		if (($uuid ne $svn_uuid) ||
+		    ($metadata_url && $url && ($url ne $metadata_url))) {
+			next;
+		}
+		if ($partial && $head) {
+			print "Partial-rebuilding $map_path ...\n";
+			print "Currently at $base_rev = $head\n";
+			$head = undef;
+		}
+
+		$self->rev_map_set($rev, $c);
+		print "r$rev = $c\n";
+	}
+	command_close_pipe($log, $ctx);
+	print "Done rebuilding $map_path\n" if (!$partial || !$head);
+	my $rev_db_path = $self->rev_db_path;
+	if (-f $self->rev_db_path) {
+		unlink $self->rev_db_path or croak "unlink: $!";
+	}
+	$self->unlink_rev_db_symlink;
+}
+
+# rev_map:
+# Tie::File seems to be prone to offset errors if revisions get sparse,
+# it's not that fast, either.  Tie::File is also not in Perl 5.6.  So
+# one of my favorite modules is out :<  Next up would be one of the DBM
+# modules, but I'm not sure which is most portable...
+#
+# This is the replacement for the rev_db format, which was too big
+# and inefficient for large repositories with a lot of sparse history
+# (mainly tags)
+#
+# The format is this:
+#   - 24 bytes for every record,
+#     * 4 bytes for the integer representing an SVN revision number
+#     * 20 bytes representing the sha1 of a git commit
+#   - No empty padding records like the old format
+#     (except the last record, which can be overwritten)
+#   - new records are written append-only since SVN revision numbers
+#     increase monotonically
+#   - lookups on SVN revision number are done via a binary search
+#   - Piping the file to xxd -c24 is a good way of dumping it for
+#     viewing or editing (piped back through xxd -r), should the need
+#     ever arise.
+#   - The last record can be padding revision with an all-zero sha1
+#     This is used to optimize fetch performance when using multiple
+#     "fetch" directives in .git/config
+#
+# These files are disposable unless noMetadata or useSvmProps is set
+
+sub _rev_map_set {
+	my ($fh, $rev, $commit) = @_;
+
+	binmode $fh or croak "binmode: $!";
+	my $size = (stat($fh))[7];
+	($size % 24) == 0 or croak "inconsistent size: $size";
+
+	my $wr_offset = 0;
+	if ($size > 0) {
+		sysseek($fh, -24, SEEK_END) or croak "seek: $!";
+		my $read = sysread($fh, my $buf, 24) or croak "read: $!";
+		$read == 24 or croak "read only $read bytes (!= 24)";
+		my ($last_rev, $last_commit) = unpack(rev_map_fmt, $buf);
+		if ($last_commit eq ('0' x40)) {
+			if ($size >= 48) {
+				sysseek($fh, -48, SEEK_END) or croak "seek: $!";
+				$read = sysread($fh, $buf, 24) or
+				    croak "read: $!";
+				$read == 24 or
+				    croak "read only $read bytes (!= 24)";
+				($last_rev, $last_commit) =
+				    unpack(rev_map_fmt, $buf);
+				if ($last_commit eq ('0' x40)) {
+					croak "inconsistent .rev_map\n";
+				}
+			}
+			if ($last_rev >= $rev) {
+				croak "last_rev is higher!: $last_rev >= $rev";
+			}
+			$wr_offset = -24;
+		}
+	}
+	sysseek($fh, $wr_offset, SEEK_END) or croak "seek: $!";
+	syswrite($fh, pack(rev_map_fmt, $rev, $commit), 24) == 24 or
+	  croak "write: $!";
+}
+
+sub _rev_map_reset {
+	my ($fh, $rev, $commit) = @_;
+	my $c = _rev_map_get($fh, $rev);
+	$c eq $commit or die "_rev_map_reset(@_) commit $c does not match!\n";
+	my $offset = sysseek($fh, 0, SEEK_CUR) or croak "seek: $!";
+	truncate $fh, $offset or croak "truncate: $!";
+}
+
+sub mkfile {
+	my ($path) = @_;
+	unless (-e $path) {
+		my ($dir, $base) = ($path =~ m#^(.*?)/?([^/]+)$#);
+		mkpath([$dir]) unless -d $dir;
+		open my $fh, '>>', $path or die "Couldn't create $path: $!\n";
+		close $fh or die "Couldn't close (create) $path: $!\n";
+	}
+}
+
+sub rev_map_set {
+	my ($self, $rev, $commit, $update_ref, $uuid) = @_;
+	defined $commit or die "missing arg3\n";
+	length $commit == 40 or die "arg3 must be a full SHA1 hexsum\n";
+	my $db = $self->map_path($uuid);
+	my $db_lock = "$db.lock";
+	my $sigmask;
+	$update_ref ||= 0;
+	if ($update_ref) {
+		$sigmask = POSIX::SigSet->new();
+		my $signew = POSIX::SigSet->new(SIGINT, SIGHUP, SIGTERM,
+			SIGALRM, SIGUSR1, SIGUSR2);
+		sigprocmask(SIG_BLOCK, $signew, $sigmask) or
+			croak "Can't block signals: $!";
+	}
+	mkfile($db);
+
+	$LOCKFILES{$db_lock} = 1;
+	my $sync;
+	# both of these options make our .rev_db file very, very important
+	# and we can't afford to lose it because rebuild() won't work
+	if ($self->use_svm_props || $self->no_metadata) {
+		$sync = 1;
+		copy($db, $db_lock) or die "rev_map_set(@_): ",
+					   "Failed to copy: ",
+					   "$db => $db_lock ($!)\n";
+	} else {
+		rename $db, $db_lock or die "rev_map_set(@_): ",
+					    "Failed to rename: ",
+					    "$db => $db_lock ($!)\n";
+	}
+
+	sysopen(my $fh, $db_lock, O_RDWR | O_CREAT)
+	     or croak "Couldn't open $db_lock: $!\n";
+	$update_ref eq 'reset' ? _rev_map_reset($fh, $rev, $commit) :
+				 _rev_map_set($fh, $rev, $commit);
+	if ($sync) {
+		$fh->flush or die "Couldn't flush $db_lock: $!\n";
+		$fh->sync or die "Couldn't sync $db_lock: $!\n";
+	}
+	close $fh or croak $!;
+	if ($update_ref) {
+		$_head = $self;
+		my $note = "";
+		$note = " ($update_ref)" if ($update_ref !~ /^\d*$/);
+		command_noisy('update-ref', '-m', "r$rev$note",
+		              $self->refname, $commit);
+	}
+	rename $db_lock, $db or die "rev_map_set(@_): ", "Failed to rename: ",
+	                            "$db_lock => $db ($!)\n";
+	delete $LOCKFILES{$db_lock};
+	if ($update_ref) {
+		sigprocmask(SIG_SETMASK, $sigmask) or
+			croak "Can't restore signal mask: $!";
+	}
+}
+
+# If want_commit, this will return an array of (rev, commit) where
+# commit _must_ be a valid commit in the archive.
+# Otherwise, it'll return the max revision (whether or not the
+# commit is valid or just a 0x40 placeholder).
+sub rev_map_max {
+	my ($self, $want_commit) = @_;
+	$self->rebuild;
+	my ($r, $c) = $self->rev_map_max_norebuild($want_commit);
+	$want_commit ? ($r, $c) : $r;
+}
+
+sub rev_map_max_norebuild {
+	my ($self, $want_commit) = @_;
+	my $map_path = $self->map_path;
+	stat $map_path or return $want_commit ? (0, undef) : 0;
+	sysopen(my $fh, $map_path, O_RDONLY) or croak "open: $!";
+	binmode $fh or croak "binmode: $!";
+	my $size = (stat($fh))[7];
+	($size % 24) == 0 or croak "inconsistent size: $size";
+
+	if ($size == 0) {
+		close $fh or croak "close: $!";
+		return $want_commit ? (0, undef) : 0;
+	}
+
+	sysseek($fh, -24, SEEK_END) or croak "seek: $!";
+	sysread($fh, my $buf, 24) == 24 or croak "read: $!";
+	my ($r, $c) = unpack(rev_map_fmt, $buf);
+	if ($want_commit && $c eq ('0' x40)) {
+		if ($size < 48) {
+			return $want_commit ? (0, undef) : 0;
+		}
+		sysseek($fh, -48, SEEK_END) or croak "seek: $!";
+		sysread($fh, $buf, 24) == 24 or croak "read: $!";
+		($r, $c) = unpack(rev_map_fmt, $buf);
+		if ($c eq ('0'x40)) {
+			croak "Penultimate record is all-zeroes in $map_path";
+		}
+	}
+	close $fh or croak "close: $!";
+	$want_commit ? ($r, $c) : $r;
+}
+
+sub rev_map_get {
+	my ($self, $rev, $uuid) = @_;
+	my $map_path = $self->map_path($uuid);
+	return undef unless -e $map_path;
+
+	sysopen(my $fh, $map_path, O_RDONLY) or croak "open: $!";
+	my $c = _rev_map_get($fh, $rev);
+	close($fh) or croak "close: $!";
+	$c
+}
+
+sub _rev_map_get {
+	my ($fh, $rev) = @_;
+
+	binmode $fh or croak "binmode: $!";
+	my $size = (stat($fh))[7];
+	($size % 24) == 0 or croak "inconsistent size: $size";
+
+	if ($size == 0) {
+		return undef;
+	}
+
+	my ($l, $u) = (0, $size - 24);
+	my ($r, $c, $buf);
+
+	while ($l <= $u) {
+		my $i = int(($l/24 + $u/24) / 2) * 24;
+		sysseek($fh, $i, SEEK_SET) or croak "seek: $!";
+		sysread($fh, my $buf, 24) == 24 or croak "read: $!";
+		my ($r, $c) = unpack(rev_map_fmt, $buf);
+
+		if ($r < $rev) {
+			$l = $i + 24;
+		} elsif ($r > $rev) {
+			$u = $i - 24;
+		} else { # $r == $rev
+			return $c eq ('0' x 40) ? undef : $c;
+		}
+	}
+	undef;
+}
+
+# Finds the first svn revision that exists on (if $eq_ok is true) or
+# before $rev for the current branch.  It will not search any lower
+# than $min_rev.  Returns the git commit hash and svn revision number
+# if found, else (undef, undef).
+sub find_rev_before {
+	my ($self, $rev, $eq_ok, $min_rev) = @_;
+	--$rev unless $eq_ok;
+	$min_rev ||= 1;
+	my $max_rev = $self->rev_map_max;
+	$rev = $max_rev if ($rev > $max_rev);
+	while ($rev >= $min_rev) {
+		if (my $c = $self->rev_map_get($rev)) {
+			return ($rev, $c);
+		}
+		--$rev;
+	}
+	return (undef, undef);
+}
+
+# Finds the first svn revision that exists on (if $eq_ok is true) or
+# after $rev for the current branch.  It will not search any higher
+# than $max_rev.  Returns the git commit hash and svn revision number
+# if found, else (undef, undef).
+sub find_rev_after {
+	my ($self, $rev, $eq_ok, $max_rev) = @_;
+	++$rev unless $eq_ok;
+	$max_rev ||= $self->rev_map_max;
+	while ($rev <= $max_rev) {
+		if (my $c = $self->rev_map_get($rev)) {
+			return ($rev, $c);
+		}
+		++$rev;
+	}
+	return (undef, undef);
+}
+
+sub _new {
+	my ($class, $repo_id, $ref_id, $path) = @_;
+	unless (defined $repo_id && length $repo_id) {
+		$repo_id = $default_repo_id;
+	}
+	unless (defined $ref_id && length $ref_id) {
+		# Access the prefix option from the git-svn main program if it's loaded.
+		my $prefix = defined &::opt_prefix ? ::opt_prefix() : "";
+		$_[2] = $ref_id =
+		             "refs/remotes/$prefix$default_ref_id";
+	}
+	$_[1] = $repo_id;
+	my $dir = "$ENV{GIT_DIR}/svn/$ref_id";
+
+	# Older repos imported by us used $GIT_DIR/svn/foo instead of
+	# $GIT_DIR/svn/refs/remotes/foo when tracking refs/remotes/foo
+	if ($ref_id =~ m{^refs/remotes/(.*)}) {
+		my $old_dir = "$ENV{GIT_DIR}/svn/$1";
+		if (-d $old_dir && ! -d $dir) {
+			$dir = $old_dir;
+		}
+	}
+
+	$_[3] = $path = '' unless (defined $path);
+	mkpath([$dir]);
+	bless {
+		ref_id => $ref_id, dir => $dir, index => "$dir/index",
+	        path => $path, config => "$ENV{GIT_DIR}/svn/config",
+	        map_root => "$dir/.rev_map", repo_id => $repo_id }, $class;
+}
+
+# for read-only access of old .rev_db formats
+sub unlink_rev_db_symlink {
+	my ($self) = @_;
+	my $link = $self->rev_db_path;
+	$link =~ s/\.[\w-]+$// or croak "missing UUID at the end of $link";
+	if (-l $link) {
+		unlink $link or croak "unlink: $link failed!";
+	}
+}
+
+sub rev_db_path {
+	my ($self, $uuid) = @_;
+	my $db_path = $self->map_path($uuid);
+	$db_path =~ s{/\.rev_map\.}{/\.rev_db\.}
+	    or croak "map_path: $db_path does not contain '/.rev_map.' !";
+	$db_path;
+}
+
+# the new replacement for .rev_db
+sub map_path {
+	my ($self, $uuid) = @_;
+	$uuid ||= $self->ra_uuid;
+	"$self->{map_root}.$uuid";
+}
+
+sub uri_encode {
+	my ($f) = @_;
+	$f =~ s#([^a-zA-Z0-9\*!\:_\./\-])#uc sprintf("%%%02x",ord($1))#eg;
+	$f
+}
+
+sub uri_decode {
+	my ($f) = @_;
+	$f =~ s#%([0-9a-fA-F]{2})#chr(hex($1))#eg;
+	$f
+}
+
+sub remove_username {
+	$_[0] =~ s{^([^:]*://)[^@]+@}{$1};
+}
+
+1;
diff --git a/perl/Makefile b/perl/Makefile
index 3478103c9..a628582bc 100644
--- a/perl/Makefile
+++ b/perl/Makefile
@@ -29,6 +29,7 @@ instdir_SQ = $(subst ','\'',$(prefix)/lib)
 
 modules += Git
 modules += Git/I18N
+modules += Git/SVN
 modules += Git/SVN/Memoize/YAML
 modules += Git/SVN/Fetcher
 modules += Git/SVN/Editor