Add 'git svn reset' to unwind 'git svn fetch'

[git/git.git] / git-svn.perl

#!/usr/bin/env perl
# Copyright (C) 2006, Eric Wong <normalperson@yhbt.net>
# License: GPL v2 or later
use warnings;
use strict;
use vars qw/	$AUTHOR $VERSION
		$sha1 $sha1_short $_revision $_repository
		$_q $_authors $_authors_prog %users/;
$AUTHOR = 'Eric Wong <normalperson@yhbt.net>';
$VERSION = '@@GIT_VERSION@@';

# From which subdir have we been invoked?
my $cmd_dir_prefix = eval {
	command_oneline([qw/rev-parse --show-prefix/], STDERR => 0)
} || '';

my $git_dir_user_set = 1 if defined $ENV{GIT_DIR};
$ENV{GIT_DIR} ||= '.git';
$Git::SVN::default_repo_id = 'svn';
$Git::SVN::default_ref_id = $ENV{GIT_SVN_ID} || 'git-svn';
$Git::SVN::Ra::_log_window_size = 100;

$Git::SVN::Log::TZ = $ENV{TZ};
$ENV{TZ} = 'UTC';
$| = 1; # unbuffer STDOUT

sub fatal (@) { print STDERR "@_\n"; exit 1 }
require SVN::Core; # use()-ing this causes segfaults for me... *shrug*
require SVN::Ra;
require SVN::Delta;
if ($SVN::Core::VERSION lt '1.1.0') {
	fatal "Need SVN::Core 1.1.0 or better (got $SVN::Core::VERSION)";
}
push @Git::SVN::Ra::ISA, 'SVN::Ra';
push @SVN::Git::Editor::ISA, 'SVN::Delta::Editor';
push @SVN::Git::Fetcher::ISA, 'SVN::Delta::Editor';
use Carp qw/croak/;
use Digest::MD5;
use IO::File qw//;
use File::Basename qw/dirname basename/;
use File::Path qw/mkpath/;
use File::Spec;
use Getopt::Long qw/:config gnu_getopt no_ignore_case auto_abbrev/;
use IPC::Open3;
use Git;

BEGIN {
	# import functions from Git into our packages, en masse
	no strict 'refs';
	foreach (qw/command command_oneline command_noisy command_output_pipe
	            command_input_pipe command_close_pipe
	            command_bidi_pipe command_close_bidi_pipe/) {
		for my $package ( qw(SVN::Git::Editor SVN::Git::Fetcher
			Git::SVN::Migration Git::SVN::Log Git::SVN),
			__PACKAGE__) {
			*{"${package}::$_"} = \&{"Git::$_"};
		}
	}
}

my ($SVN);

$sha1 = qr/[a-f\d]{40}/;
$sha1_short = qr/[a-f\d]{4,40}/;
my ($_stdin, $_help, $_edit,
	$_message, $_file,
	$_template, $_shared,
	$_version, $_fetch_all, $_no_rebase, $_fetch_parent,
	$_merge, $_strategy, $_dry_run, $_local,
	$_prefix, $_no_checkout, $_url, $_verbose,
	$_git_format, $_commit_url, $_tag);
$Git::SVN::_follow_parent = 1;
$_q ||= 0;
my %remote_opts = ( 'username=s' => \$Git::SVN::Prompt::_username,
                    'config-dir=s' => \$Git::SVN::Ra::config_dir,
                    'no-auth-cache' => \$Git::SVN::Prompt::_no_auth_cache,
                    'ignore-paths=s' => \$SVN::Git::Fetcher::_ignore_regex );
my %fc_opts = ( 'follow-parent|follow!' => \$Git::SVN::_follow_parent,
		'authors-file|A=s' => \$_authors,
		'authors-prog=s' => \$_authors_prog,
		'repack:i' => \$Git::SVN::_repack,
		'noMetadata' => \$Git::SVN::_no_metadata,
		'useSvmProps' => \$Git::SVN::_use_svm_props,
		'useSvnsyncProps' => \$Git::SVN::_use_svnsync_props,
		'log-window-size=i' => \$Git::SVN::Ra::_log_window_size,
		'no-checkout' => \$_no_checkout,
		'quiet|q+' => \$_q,
		'repack-flags|repack-args|repack-opts=s' =>
		   \$Git::SVN::_repack_flags,
		'use-log-author' => \$Git::SVN::_use_log_author,
		'add-author-from' => \$Git::SVN::_add_author_from,
		'localtime' => \$Git::SVN::_localtime,
		%remote_opts );

my ($_trunk, $_tags, $_branches, $_stdlayout);
my %icv;
my %init_opts = ( 'template=s' => \$_template, 'shared:s' => \$_shared,
                  'trunk|T=s' => \$_trunk, 'tags|t=s' => \$_tags,
                  'branches|b=s' => \$_branches, 'prefix=s' => \$_prefix,
                  'stdlayout|s' => \$_stdlayout,
                  'minimize-url|m' => \$Git::SVN::_minimize_url,
		  'no-metadata' => sub { $icv{noMetadata} = 1 },
		  'use-svm-props' => sub { $icv{useSvmProps} = 1 },
		  'use-svnsync-props' => sub { $icv{useSvnsyncProps} = 1 },
		  'rewrite-root=s' => sub { $icv{rewriteRoot} = $_[1] },
                  %remote_opts );
my %cmt_opts = ( 'edit|e' => \$_edit,
		'rmdir' => \$SVN::Git::Editor::_rmdir,
		'find-copies-harder' => \$SVN::Git::Editor::_find_copies_harder,
		'l=i' => \$SVN::Git::Editor::_rename_limit,
		'copy-similarity|C=i'=> \$SVN::Git::Editor::_cp_similarity
);

my %cmd = (
	fetch => [ \&cmd_fetch, "Download new revisions from SVN",
			{ 'revision|r=s' => \$_revision,
			  'fetch-all|all' => \$_fetch_all,
			  'parent|p' => \$_fetch_parent,
			   %fc_opts } ],
	clone => [ \&cmd_clone, "Initialize and fetch revisions",
			{ 'revision|r=s' => \$_revision,
			   %fc_opts, %init_opts } ],
	init => [ \&cmd_init, "Initialize a repo for tracking" .
			  " (requires URL argument)",
			  \%init_opts ],
	'multi-init' => [ \&cmd_multi_init,
	                  "Deprecated alias for ".
			  "'$0 init -T<trunk> -b<branches> -t<tags>'",
			  \%init_opts ],
	dcommit => [ \&cmd_dcommit,
	             'Commit several diffs to merge with upstream',
			{ 'merge|m|M' => \$_merge,
			  'strategy|s=s' => \$_strategy,
			  'verbose|v' => \$_verbose,
			  'dry-run|n' => \$_dry_run,
			  'fetch-all|all' => \$_fetch_all,
			  'commit-url=s' => \$_commit_url,
			  'revision|r=i' => \$_revision,
			  'no-rebase' => \$_no_rebase,
			%cmt_opts, %fc_opts } ],
	branch => [ \&cmd_branch,
	            'Create a branch in the SVN repository',
	            { 'message|m=s' => \$_message,
	              'dry-run|n' => \$_dry_run,
		      'tag|t' => \$_tag } ],
	tag => [ sub { $_tag = 1; cmd_branch(@_) },
	         'Create a tag in the SVN repository',
	         { 'message|m=s' => \$_message,
	           'dry-run|n' => \$_dry_run } ],
	'set-tree' => [ \&cmd_set_tree,
	                "Set an SVN repository to a git tree-ish",
			{ 'stdin' => \$_stdin, %cmt_opts, %fc_opts, } ],
	'create-ignore' => [ \&cmd_create_ignore,
			     'Create a .gitignore per svn:ignore',
			     { 'revision|r=i' => \$_revision
			     } ],
        'propget' => [ \&cmd_propget,
		       'Print the value of a property on a file or directory',
		       { 'revision|r=i' => \$_revision } ],
        'proplist' => [ \&cmd_proplist,
		       'List all properties of a file or directory',
		       { 'revision|r=i' => \$_revision } ],
	'show-ignore' => [ \&cmd_show_ignore, "Show svn:ignore listings",
			{ 'revision|r=i' => \$_revision
			} ],
	'show-externals' => [ \&cmd_show_externals, "Show svn:externals listings",
			{ 'revision|r=i' => \$_revision
			} ],
	'multi-fetch' => [ \&cmd_multi_fetch,
	                   "Deprecated alias for $0 fetch --all",
			   { 'revision|r=s' => \$_revision, %fc_opts } ],
	'migrate' => [ sub { },
	               # no-op, we automatically run this anyways,
	               'Migrate configuration/metadata/layout from
		        previous versions of git-svn',
                       { 'minimize' => \$Git::SVN::Migration::_minimize,
			 %remote_opts } ],
	'log' => [ \&Git::SVN::Log::cmd_show_log, 'Show commit logs',
			{ 'limit=i' => \$Git::SVN::Log::limit,
			  'revision|r=s' => \$_revision,
			  'verbose|v' => \$Git::SVN::Log::verbose,
			  'incremental' => \$Git::SVN::Log::incremental,
			  'oneline' => \$Git::SVN::Log::oneline,
			  'show-commit' => \$Git::SVN::Log::show_commit,
			  'non-recursive' => \$Git::SVN::Log::non_recursive,
			  'authors-file|A=s' => \$_authors,
			  'color' => \$Git::SVN::Log::color,
			  'pager=s' => \$Git::SVN::Log::pager
			} ],
	'find-rev' => [ \&cmd_find_rev,
	                "Translate between SVN revision numbers and tree-ish",
			{} ],
	'rebase' => [ \&cmd_rebase, "Fetch and rebase your working directory",
			{ 'merge|m|M' => \$_merge,
			  'verbose|v' => \$_verbose,
			  'strategy|s=s' => \$_strategy,
			  'local|l' => \$_local,
			  'fetch-all|all' => \$_fetch_all,
			  'dry-run|n' => \$_dry_run,
			  %fc_opts } ],
	'commit-diff' => [ \&cmd_commit_diff,
	                   'Commit a diff between two trees',
			{ 'message|m=s' => \$_message,
			  'file|F=s' => \$_file,
			  'revision|r=s' => \$_revision,
			%cmt_opts } ],
	'info' => [ \&cmd_info,
		    "Show info about the latest SVN revision
		     on the current branch",
		    { 'url' => \$_url, } ],
	'blame' => [ \&Git::SVN::Log::cmd_blame,
	            "Show what revision and author last modified each line of a file",
		    { 'git-format' => \$_git_format } ],
	'reset' => [ \&cmd_reset,
		     "Undo fetches back to the specified SVN revision",
		     { 'revision|r=s' => \$_revision,
		       'parent|p' => \$_fetch_parent } ],
);

my $cmd;
for (my $i = 0; $i < @ARGV; $i++) {
	if (defined $cmd{$ARGV[$i]}) {
		$cmd = $ARGV[$i];
		splice @ARGV, $i, 1;
		last;
	} elsif ($ARGV[$i] eq 'help') {
		$cmd = $ARGV[$i+1];
		usage(0);
	}
};

# make sure we're always running at the top-level working directory
unless ($cmd && $cmd =~ /(?:clone|init|multi-init)$/) {
	unless (-d $ENV{GIT_DIR}) {
		if ($git_dir_user_set) {
			die "GIT_DIR=$ENV{GIT_DIR} explicitly set, ",
			    "but it is not a directory\n";
		}
		my $git_dir = delete $ENV{GIT_DIR};
		my $cdup = undef;
		git_cmd_try {
			$cdup = command_oneline(qw/rev-parse --show-cdup/);
			$git_dir = '.' unless ($cdup);
			chomp $cdup if ($cdup);
			$cdup = "." unless ($cdup && length $cdup);
		} "Already at toplevel, but $git_dir not found\n";
		chdir $cdup or die "Unable to chdir up to '$cdup'\n";
		unless (-d $git_dir) {
			die "$git_dir still not found after going to ",
			    "'$cdup'\n";
		}
		$ENV{GIT_DIR} = $git_dir;
	}
	$_repository = Git->repository(Repository => $ENV{GIT_DIR});
}

my %opts = %{$cmd{$cmd}->[2]} if (defined $cmd);

read_repo_config(\%opts);
if ($cmd && ($cmd eq 'log' || $cmd eq 'blame')) {
	Getopt::Long::Configure('pass_through');
}
my $rv = GetOptions(%opts, 'help|H|h' => \$_help, 'version|V' => \$_version,
                    'minimize-connections' => \$Git::SVN::Migration::_minimize,
                    'id|i=s' => \$Git::SVN::default_ref_id,
                    'svn-remote|remote|R=s' => sub {
                       $Git::SVN::no_reuse_existing = 1;
                       $Git::SVN::default_repo_id = $_[1] });
exit 1 if (!$rv && $cmd && $cmd ne 'log');

usage(0) if $_help;
version() if $_version;
usage(1) unless defined $cmd;
load_authors() if $_authors;
if (defined $_authors_prog) {
	$_authors_prog = "'" . File::Spec->rel2abs($_authors_prog) . "'";
}

unless ($cmd =~ /^(?:clone|init|multi-init|commit-diff)$/) {
	Git::SVN::Migration::migration_check();
}
Git::SVN::init_vars();
eval {
	Git::SVN::verify_remotes_sanity();
	$cmd{$cmd}->[0]->(@ARGV);
};
fatal $@ if $@;
post_fetch_checkout();
exit 0;

####################### primary functions ######################
sub usage {
	my $exit = shift || 0;
	my $fd = $exit ? \*STDERR : \*STDOUT;
	print $fd <<"";
git-svn - bidirectional operations between a single Subversion tree and git
Usage: git svn <command> [options] [arguments]\n

	print $fd "Available commands:\n" unless $cmd;

	foreach (sort keys %cmd) {
		next if $cmd && $cmd ne $_;
		next if /^multi-/; # don't show deprecated commands
		print $fd '  ',pack('A17',$_),$cmd{$_}->[1],"\n";
		foreach (sort keys %{$cmd{$_}->[2]}) {
			# mixed-case options are for .git/config only
			next if /[A-Z]/ && /^[a-z]+$/i;
			# prints out arguments as they should be passed:
			my $x = s#[:=]s$## ? '<arg>' : s#[:=]i$## ? '<num>' : '';
			print $fd ' ' x 21, join(', ', map { length $_ > 1 ?
							"--$_" : "-$_" }
						split /\|/,$_)," $x\n";
		}
	}
	print $fd <<"";
\nGIT_SVN_ID may be set in the environment or via the --id/-i switch to an
arbitrary identifier if you're tracking multiple SVN branches/repositories in
one git repository and want to keep them separate.  See git-svn(1) for more
information.

	exit $exit;
}

sub version {
	print "git-svn version $VERSION (svn $SVN::Core::VERSION)\n";
	exit 0;
}

sub do_git_init_db {
	unless (-d $ENV{GIT_DIR}) {
		my @init_db = ('init');
		push @init_db, "--template=$_template" if defined $_template;
		if (defined $_shared) {
			if ($_shared =~ /[a-z]/) {
				push @init_db, "--shared=$_shared";
			} else {
				push @init_db, "--shared";
			}
		}
		command_noisy(@init_db);
		$_repository = Git->repository(Repository => ".git");
	}
	command_noisy('config', 'core.autocrlf', 'false');
	my $set;
	my $pfx = "svn-remote.$Git::SVN::default_repo_id";
	foreach my $i (keys %icv) {
		die "'$set' and '$i' cannot both be set\n" if $set;
		next unless defined $icv{$i};
		command_noisy('config', "$pfx.$i", $icv{$i});
		$set = $i;
	}
	my $ignore_regex = \$SVN::Git::Fetcher::_ignore_regex;
	command_noisy('config', "$pfx.ignore-paths", $$ignore_regex)
		if defined $$ignore_regex;
}

sub init_subdir {
	my $repo_path = shift or return;
	mkpath([$repo_path]) unless -d $repo_path;
	chdir $repo_path or die "Couldn't chdir to $repo_path: $!\n";
	$ENV{GIT_DIR} = '.git';
	$_repository = Git->repository(Repository => $ENV{GIT_DIR});
}

sub cmd_clone {
	my ($url, $path) = @_;
	if (!defined $path &&
	    (defined $_trunk || defined $_branches || defined $_tags ||
	     defined $_stdlayout) &&
	    $url !~ m#^[a-z\+]+://#) {
		$path = $url;
	}
	$path = basename($url) if !defined $path || !length $path;
	cmd_init($url, $path);
	Git::SVN::fetch_all($Git::SVN::default_repo_id);
	command_oneline('config', 'svn.authorsfile', $_authors) if $_authors;
}

sub cmd_init {
	if (defined $_stdlayout) {
		$_trunk = 'trunk' if (!defined $_trunk);
		$_tags = 'tags' if (!defined $_tags);
		$_branches = 'branches' if (!defined $_branches);
	}
	if (defined $_trunk || defined $_branches || defined $_tags) {
		return cmd_multi_init(@_);
	}
	my $url = shift or die "SVN repository location required ",
	                       "as a command-line argument\n";
	init_subdir(@_);
	do_git_init_db();

	Git::SVN->init($url);
}

sub cmd_fetch {
	if (grep /^\d+=./, @_) {
		die "'<rev>=<commit>' fetch arguments are ",
		    "no longer supported.\n";
	}
	my ($remote) = @_;
	if (@_ > 1) {
		die "Usage: $0 fetch [--all] [--parent] [svn-remote]\n";
	}
	if ($_fetch_parent) {
		my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
		unless ($gs) {
			die "Unable to determine upstream SVN information from ",
			    "working tree history\n";
		}
	        # just fetch, don't checkout.
		$_no_checkout = 'true';
		$_fetch_all ? $gs->fetch_all : $gs->fetch;
	} elsif ($_fetch_all) {
		cmd_multi_fetch();
	} else {
		$remote ||= $Git::SVN::default_repo_id;
		Git::SVN::fetch_all($remote, Git::SVN::read_all_remotes());
	}
}

sub cmd_set_tree {
	my (@commits) = @_;
	if ($_stdin || !@commits) {
		print "Reading from stdin...\n";
		@commits = ();
		while (<STDIN>) {
			if (/\b($sha1_short)\b/o) {
				unshift @commits, $1;
			}
		}
	}
	my @revs;
	foreach my $c (@commits) {
		my @tmp = command('rev-parse',$c);
		if (scalar @tmp == 1) {
			push @revs, $tmp[0];
		} elsif (scalar @tmp > 1) {
			push @revs, reverse(command('rev-list',@tmp));
		} else {
			fatal "Failed to rev-parse $c";
		}
	}
	my $gs = Git::SVN->new;
	my ($r_last, $cmt_last) = $gs->last_rev_commit;
	$gs->fetch;
	if (defined $gs->{last_rev} && $r_last != $gs->{last_rev}) {
		fatal "There are new revisions that were fetched ",
		      "and need to be merged (or acknowledged) ",
		      "before committing.\nlast rev: $r_last\n",
		      " current: $gs->{last_rev}";
	}
	$gs->set_tree($_) foreach @revs;
	print "Done committing ",scalar @revs," revisions to SVN\n";
	unlink $gs->{index};
}

sub cmd_dcommit {
	my $head = shift;
	git_cmd_try { command_oneline(qw/diff-index --quiet HEAD/) }
		'Cannot dcommit with a dirty index.  Commit your changes first, '
		. "or stash them with `git stash'.\n";
	$head ||= 'HEAD';

	my $old_head;
	if ($head ne 'HEAD') {
		$old_head = eval {
			command_oneline([qw/symbolic-ref -q HEAD/])
		};
		if ($old_head) {
			$old_head =~ s{^refs/heads/}{};
		} else {
			$old_head = eval { command_oneline(qw/rev-parse HEAD/) };
		}
		command(['checkout', $head], STDERR => 0);
	}

	my @refs;
	my ($url, $rev, $uuid, $gs) = working_head_info('HEAD', \@refs);
	unless ($gs) {
		die "Unable to determine upstream SVN information from ",
		    "$head history.\nPerhaps the repository is empty.";
	}

	if (defined $_commit_url) {
		$url = $_commit_url;
	} else {
		$url = eval { command_oneline('config', '--get',
			      "svn-remote.$gs->{repo_id}.commiturl") };
		if (!$url) {
			$url = $gs->full_url
		}
	}

	my $last_rev = $_revision if defined $_revision;
	if ($url) {
		print "Committing to $url ...\n";
	}
	my ($linear_refs, $parents) = linearize_history($gs, \@refs);
	if ($_no_rebase && scalar(@$linear_refs) > 1) {
		warn "Attempting to commit more than one change while ",
		     "--no-rebase is enabled.\n",
		     "If these changes depend on each other, re-running ",
		     "without --no-rebase may be required."
	}
	my $expect_url = $url;
	Git::SVN::remove_username($expect_url);
	while (1) {
		my $d = shift @$linear_refs or last;
		unless (defined $last_rev) {
			(undef, $last_rev, undef) = cmt_metadata("$d~1");
			unless (defined $last_rev) {
				fatal "Unable to extract revision information ",
				      "from commit $d~1";
			}
		}
		if ($_dry_run) {
			print "diff-tree $d~1 $d\n";
		} else {
			my $cmt_rev;
			my %ed_opts = ( r => $last_rev,
			                log => get_commit_entry($d)->{log},
			                ra => Git::SVN::Ra->new($url),
			                config => SVN::Core::config_get_config(
			                        $Git::SVN::Ra::config_dir
			                ),
			                tree_a => "$d~1",
			                tree_b => $d,
			                editor_cb => sub {
			                       print "Committed r$_[0]\n";
			                       $cmt_rev = $_[0];
			                },
			                svn_path => '');
			if (!SVN::Git::Editor->new(\%ed_opts)->apply_diff) {
				print "No changes\n$d~1 == $d\n";
			} elsif ($parents->{$d} && @{$parents->{$d}}) {
				$gs->{inject_parents_dcommit}->{$cmt_rev} =
				                               $parents->{$d};
			}
			$_fetch_all ? $gs->fetch_all : $gs->fetch;
			$last_rev = $cmt_rev;
			next if $_no_rebase;

			# we always want to rebase against the current HEAD,
			# not any head that was passed to us
			my @diff = command('diff-tree', $d,
			                   $gs->refname, '--');
			my @finish;
			if (@diff) {
				@finish = rebase_cmd();
				print STDERR "W: $d and ", $gs->refname,
				             " differ, using @finish:\n",
				             join("\n", @diff), "\n";
			} else {
				print "No changes between current HEAD and ",
				      $gs->refname,
				      "\nResetting to the latest ",
				      $gs->refname, "\n";
				@finish = qw/reset --mixed/;
			}
			command_noisy(@finish, $gs->refname);
			if (@diff) {
				@refs = ();
				my ($url_, $rev_, $uuid_, $gs_) =
				              working_head_info('HEAD', \@refs);
				my ($linear_refs_, $parents_) =
				              linearize_history($gs_, \@refs);
				if (scalar(@$linear_refs) !=
				    scalar(@$linear_refs_)) {
					fatal "# of revisions changed ",
					  "\nbefore:\n",
					  join("\n", @$linear_refs),
					  "\n\nafter:\n",
					  join("\n", @$linear_refs_), "\n",
					  'If you are attempting to commit ',
					  "merges, try running:\n\t",
					  'git rebase --interactive',
					  '--preserve-merges ',
					  $gs->refname,
					  "\nBefore dcommitting";
				}
				if ($url_ ne $expect_url) {
					fatal "URL mismatch after rebase: ",
					      "$url_ != $expect_url";
				}
				if ($uuid_ ne $uuid) {
					fatal "uuid mismatch after rebase: ",
					      "$uuid_ != $uuid";
				}
				# remap parents
				my (%p, @l, $i);
				for ($i = 0; $i < scalar @$linear_refs; $i++) {
					my $new = $linear_refs_->[$i] or next;
					$p{$new} =
						$parents->{$linear_refs->[$i]};
					push @l, $new;
				}
				$parents = \%p;
				$linear_refs = \@l;
			}
		}
	}

	if ($old_head) {
		my $new_head = command_oneline(qw/rev-parse HEAD/);
		my $new_is_symbolic = eval {
			command_oneline(qw/symbolic-ref -q HEAD/);
		};
		if ($new_is_symbolic) {
			print "dcommitted the branch ", $head, "\n";
		} else {
			print "dcommitted on a detached HEAD because you gave ",
			      "a revision argument.\n",
			      "The rewritten commit is: ", $new_head, "\n";
		}
		command(['checkout', $old_head], STDERR => 0);
	}

	unlink $gs->{index};
}

sub cmd_branch {
	my ($branch_name, $head) = @_;

	unless (defined $branch_name && length $branch_name) {
		die(($_tag ? "tag" : "branch") . " name required\n");
	}
	$head ||= 'HEAD';

	my ($src, $rev, undef, $gs) = working_head_info($head);

	my $remote = Git::SVN::read_all_remotes()->{$gs->{repo_id}};
	my $glob = $remote->{ $_tag ? 'tags' : 'branches' };
	my ($lft, $rgt) = @{ $glob->{path} }{qw/left right/};
	my $dst = join '/', $remote->{url}, $lft, $branch_name, ($rgt || ());

	my $ctx = SVN::Client->new(
		auth    => Git::SVN::Ra::_auth_providers(),
		log_msg => sub {
			${ $_[0] } = defined $_message
				? $_message
				: 'Create ' . ($_tag ? 'tag ' : 'branch ' )
				. $branch_name;
		},
	);

	eval {
		$ctx->ls($dst, 'HEAD', 0);
	} and die "branch ${branch_name} already exists\n";

	print "Copying ${src} at r${rev} to ${dst}...\n";
	$ctx->copy($src, $rev, $dst)
		unless $_dry_run;

	$gs->fetch_all;
}

sub cmd_find_rev {
	my $revision_or_hash = shift or die "SVN or git revision required ",
	                                    "as a command-line argument\n";
	my $result;
	if ($revision_or_hash =~ /^r\d+$/) {
		my $head = shift;
		$head ||= 'HEAD';
		my @refs;
		my (undef, undef, $uuid, $gs) = working_head_info($head, \@refs);
		unless ($gs) {
			die "Unable to determine upstream SVN information from ",
			    "$head history\n";
		}
		my $desired_revision = substr($revision_or_hash, 1);
		$result = $gs->rev_map_get($desired_revision, $uuid);
	} else {
		my (undef, $rev, undef) = cmt_metadata($revision_or_hash);
		$result = $rev;
	}
	print "$result\n" if $result;
}

sub cmd_rebase {
	command_noisy(qw/update-index --refresh/);
	my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
	unless ($gs) {
		die "Unable to determine upstream SVN information from ",
		    "working tree history\n";
	}
	if ($_dry_run) {
		print "Remote Branch: " . $gs->refname . "\n";
		print "SVN URL: " . $url . "\n";
		return;
	}
	if (command(qw/diff-index HEAD --/)) {
		print STDERR "Cannot rebase with uncommited changes:\n";
		command_noisy('status');
		exit 1;
	}
	unless ($_local) {
		# rebase will checkout for us, so no need to do it explicitly
		$_no_checkout = 'true';
		$_fetch_all ? $gs->fetch_all : $gs->fetch;
	}
	command_noisy(rebase_cmd(), $gs->refname);
}

sub cmd_show_ignore {
	my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
	$gs ||= Git::SVN->new;
	my $r = (defined $_revision ? $_revision : $gs->ra->get_latest_revnum);
	$gs->prop_walk($gs->{path}, $r, sub {
		my ($gs, $path, $props) = @_;
		print STDOUT "\n# $path\n";
		my $s = $props->{'svn:ignore'} or return;
		$s =~ s/[\r\n]+/\n/g;
		chomp $s;
		$s =~ s#^#$path#gm;
		print STDOUT "$s\n";
	});
}

sub cmd_show_externals {
	my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
	$gs ||= Git::SVN->new;
	my $r = (defined $_revision ? $_revision : $gs->ra->get_latest_revnum);
	$gs->prop_walk($gs->{path}, $r, sub {
		my ($gs, $path, $props) = @_;
		print STDOUT "\n# $path\n";
		my $s = $props->{'svn:externals'} or return;
		$s =~ s/[\r\n]+/\n/g;
		chomp $s;
		$s =~ s#^#$path#gm;
		print STDOUT "$s\n";
	});
}

sub cmd_create_ignore {
	my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
	$gs ||= Git::SVN->new;
	my $r = (defined $_revision ? $_revision : $gs->ra->get_latest_revnum);
	$gs->prop_walk($gs->{path}, $r, sub {
		my ($gs, $path, $props) = @_;
		# $path is of the form /path/to/dir/
		$path = '.' . $path;
		# SVN can have attributes on empty directories,
		# which git won't track
		mkpath([$path]) unless -d $path;
		my $ignore = $path . '.gitignore';
		my $s = $props->{'svn:ignore'} or return;
		open(GITIGNORE, '>', $ignore)
		  or fatal("Failed to open `$ignore' for writing: $!");
		$s =~ s/[\r\n]+/\n/g;
		chomp $s;
		# Prefix all patterns so that the ignore doesn't apply
		# to sub-directories.
		$s =~ s#^#/#gm;
		print GITIGNORE "$s\n";
		close(GITIGNORE)
		  or fatal("Failed to close `$ignore': $!");
		command_noisy('add', '-f', $ignore);
	});
}

sub canonicalize_path {
	my ($path) = @_;
	my $dot_slash_added = 0;
	if (substr($path, 0, 1) ne "/") {
		$path = "./" . $path;
		$dot_slash_added = 1;
	}
	# File::Spec->canonpath doesn't collapse x/../y into y (for a
	# good reason), so let's do this manually.
	$path =~ s#/+#/#g;
	$path =~ s#/\.(?:/|$)#/#g;
	$path =~ s#/[^/]+/\.\.##g;
	$path =~ s#/$##g;
	$path =~ s#^\./## if $dot_slash_added;
	$path =~ s#^/##;
	$path =~ s#^\.$##;
	return $path;
}

# get_svnprops(PATH)
# ------------------
# Helper for cmd_propget and cmd_proplist below.
sub get_svnprops {
	my $path = shift;
	my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
	$gs ||= Git::SVN->new;

	# prefix THE PATH by the sub-directory from which the user
	# invoked us.
	$path = $cmd_dir_prefix . $path;
	fatal("No such file or directory: $path") unless -e $path;
	my $is_dir = -d $path ? 1 : 0;
	$path = $gs->{path} . '/' . $path;

	# canonicalize the path (otherwise libsvn will abort or fail to
	# find the file)
	$path = canonicalize_path($path);

	my $r = (defined $_revision ? $_revision : $gs->ra->get_latest_revnum);
	my $props;
	if ($is_dir) {
		(undef, undef, $props) = $gs->ra->get_dir($path, $r);
	}
	else {
		(undef, $props) = $gs->ra->get_file($path, $r, undef);
	}
	return $props;
}

# cmd_propget (PROP, PATH)
# ------------------------
# Print the SVN property PROP for PATH.
sub cmd_propget {
	my ($prop, $path) = @_;
	$path = '.' if not defined $path;
	usage(1) if not defined $prop;
	my $props = get_svnprops($path);
	if (not defined $props->{$prop}) {
		fatal("`$path' does not have a `$prop' SVN property.");
	}
	print $props->{$prop} . "\n";
}

# cmd_proplist (PATH)
# -------------------
# Print the list of SVN properties for PATH.
sub cmd_proplist {
	my $path = shift;
	$path = '.' if not defined $path;
	my $props = get_svnprops($path);
	print "Properties on '$path':\n";
	foreach (sort keys %{$props}) {
		print "  $_\n";
	}
}

sub cmd_multi_init {
	my $url = shift;
	unless (defined $_trunk || defined $_branches || defined $_tags) {
		usage(1);
	}

	# there are currently some bugs that prevent multi-init/multi-fetch
	# setups from working well without this.
	$Git::SVN::_minimize_url = 1;

	$_prefix = '' unless defined $_prefix;
	if (defined $url) {
		$url =~ s#/+$##;
		init_subdir(@_);
	}
	do_git_init_db();
	if (defined $_trunk) {
		my $trunk_ref = $_prefix . 'trunk';
		# try both old-style and new-style lookups:
		my $gs_trunk = eval { Git::SVN->new($trunk_ref) };
		unless ($gs_trunk) {
			my ($trunk_url, $trunk_path) =
			                      complete_svn_url($url, $_trunk);
			$gs_trunk = Git::SVN->init($trunk_url, $trunk_path,
						   undef, $trunk_ref);
		}
	}
	return unless defined $_branches || defined $_tags;
	my $ra = $url ? Git::SVN::Ra->new($url) : undef;
	complete_url_ls_init($ra, $_branches, '--branches/-b', $_prefix);
	complete_url_ls_init($ra, $_tags, '--tags/-t', $_prefix . 'tags/');
}

sub cmd_multi_fetch {
	my $remotes = Git::SVN::read_all_remotes();
	foreach my $repo_id (sort keys %$remotes) {
		if ($remotes->{$repo_id}->{url}) {
			Git::SVN::fetch_all($repo_id, $remotes);
		}
	}
}

# this command is special because it requires no metadata
sub cmd_commit_diff {
	my ($ta, $tb, $url) = @_;
	my $usage = "Usage: $0 commit-diff -r<revision> ".
	            "<tree-ish> <tree-ish> [<URL>]";
	fatal($usage) if (!defined $ta || !defined $tb);
	my $svn_path = '';
	if (!defined $url) {
		my $gs = eval { Git::SVN->new };
		if (!$gs) {
			fatal("Needed URL or usable git-svn --id in ",
			      "the command-line\n", $usage);
		}
		$url = $gs->{url};
		$svn_path = $gs->{path};
	}
	unless (defined $_revision) {
		fatal("-r|--revision is a required argument\n", $usage);
	}
	if (defined $_message && defined $_file) {
		fatal("Both --message/-m and --file/-F specified ",
		      "for the commit message.\n",
		      "I have no idea what you mean");
	}
	if (defined $_file) {
		$_message = file_to_s($_file);
	} else {
		$_message ||= get_commit_entry($tb)->{log};
	}
	my $ra ||= Git::SVN::Ra->new($url);
	my $r = $_revision;
	if ($r eq 'HEAD') {
		$r = $ra->get_latest_revnum;
	} elsif ($r !~ /^\d+$/) {
		die "revision argument: $r not understood by git-svn\n";
	}
	my %ed_opts = ( r => $r,
	                log => $_message,
	                ra => $ra,
	                tree_a => $ta,
	                tree_b => $tb,
	                editor_cb => sub { print "Committed r$_[0]\n" },
	                svn_path => $svn_path );
	if (!SVN::Git::Editor->new(\%ed_opts)->apply_diff) {
		print "No changes\n$ta == $tb\n";
	}
}

sub escape_uri_only {
	my ($uri) = @_;
	my @tmp;
	foreach (split m{/}, $uri) {
		s/([^~\w.%+-]|%(?![a-fA-F0-9]{2}))/sprintf("%%%02X",ord($1))/eg;
		push @tmp, $_;
	}
	join('/', @tmp);
}

sub escape_url {
	my ($url) = @_;
	if ($url =~ m#^([^:]+)://([^/]*)(.*)$#) {
		my ($scheme, $domain, $uri) = ($1, $2, escape_uri_only($3));
		$url = "$scheme://$domain$uri";
	}
	$url;
}

sub cmd_info {
	my $path = canonicalize_path(defined($_[0]) ? $_[0] : ".");
	my $fullpath = canonicalize_path($cmd_dir_prefix . $path);
	if (exists $_[1]) {
		die "Too many arguments specified\n";
	}

	my ($file_type, $diff_status) = find_file_type_and_diff_status($path);

	if (!$file_type && !$diff_status) {
		print STDERR "svn: '$path' is not under version control\n";
		exit 1;
	}

	my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
	unless ($gs) {
		die "Unable to determine upstream SVN information from ",
		    "working tree history\n";
	}

	# canonicalize_path() will return "" to make libsvn 1.5.x happy,
	$path = "." if $path eq "";

	my $full_url = $url . ($fullpath eq "" ? "" : "/$fullpath");

	if ($_url) {
		print escape_url($full_url), "\n";
		return;
	}

	my $result = "Path: $path\n";
	$result .= "Name: " . basename($path) . "\n" if $file_type ne "dir";
	$result .= "URL: " . escape_url($full_url) . "\n";

	eval {
		my $repos_root = $gs->repos_root;
		Git::SVN::remove_username($repos_root);
		$result .= "Repository Root: " . escape_url($repos_root) . "\n";
	};
	if ($@) {
		$result .= "Repository Root: (offline)\n";
	}
	$result .= "Repository UUID: $uuid\n" unless $diff_status eq "A" &&
		($SVN::Core::VERSION le '1.5.4' || $file_type ne "dir");
	$result .= "Revision: " . ($diff_status eq "A" ? 0 : $rev) . "\n";

	$result .= "Node Kind: " .
		   ($file_type eq "dir" ? "directory" : "file") . "\n";

	my $schedule = $diff_status eq "A"
		       ? "add"
		       : ($diff_status eq "D" ? "delete" : "normal");
	$result .= "Schedule: $schedule\n";

	if ($diff_status eq "A") {
		print $result, "\n";
		return;
	}

	my ($lc_author, $lc_rev, $lc_date_utc);
	my @args = Git::SVN::Log::git_svn_log_cmd($rev, $rev, "--", $fullpath);
	my $log = command_output_pipe(@args);
	my $esc_color = qr/(?:\033\[(?:(?:\d+;)*\d*)?m)*/;
	while (<$log>) {
		if (/^${esc_color}author (.+) <[^>]+> (\d+) ([\-\+]?\d+)$/o) {
			$lc_author = $1;
			$lc_date_utc = Git::SVN::Log::parse_git_date($2, $3);
		} elsif (/^${esc_color}    (git-svn-id:.+)$/o) {
			(undef, $lc_rev, undef) = ::extract_metadata($1);
		}
	}
	close $log;

	Git::SVN::Log::set_local_timezone();

	$result .= "Last Changed Author: $lc_author\n";
	$result .= "Last Changed Rev: $lc_rev\n";
	$result .= "Last Changed Date: " .
		   Git::SVN::Log::format_svn_date($lc_date_utc) . "\n";

	if ($file_type ne "dir") {
		my $text_last_updated_date =
		    ($diff_status eq "D" ? $lc_date_utc : (stat $path)[9]);
		$result .=
		    "Text Last Updated: " .
		    Git::SVN::Log::format_svn_date($text_last_updated_date) .
		    "\n";
		my $checksum;
		if ($diff_status eq "D") {
			my ($fh, $ctx) =
			    command_output_pipe(qw(cat-file blob), "HEAD:$path");
			if ($file_type eq "link") {
				my $file_name = <$fh>;
				$checksum = md5sum("link $file_name");
			} else {
				$checksum = md5sum($fh);
			}
			command_close_pipe($fh, $ctx);
		} elsif ($file_type eq "link") {
			my $file_name =
			    command(qw(cat-file blob), "HEAD:$path");
			$checksum =
			    md5sum("link " . $file_name);
		} else {
			open FILE, "<", $path or die $!;
			$checksum = md5sum(\*FILE);
			close FILE or die $!;
		}
		$result .= "Checksum: " . $checksum . "\n";
	}

	print $result, "\n";
}

sub cmd_reset {
	my $target = shift || $_revision or die "SVN revision required\n";
	$target = $1 if $target =~ /^r(\d+)$/;
	$target =~ /^\d+$/ or die "Numeric SVN revision expected\n";
	my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
	unless ($gs) {
		die "Unable to determine upstream SVN information from ".
		    "history\n";
	}
	my ($r, $c) = $gs->find_rev_before($target, not $_fetch_parent);
	$gs->rev_map_set($r, $c, 'reset', $uuid);
	print "r$r = $c ($gs->{ref_id})\n";
}

########################### utility functions #########################

sub rebase_cmd {
	my @cmd = qw/rebase/;
	push @cmd, '-v' if $_verbose;
	push @cmd, qw/--merge/ if $_merge;
	push @cmd, "--strategy=$_strategy" if $_strategy;
	@cmd;
}

sub post_fetch_checkout {
	return if $_no_checkout;
	my $gs = $Git::SVN::_head or return;
	return if verify_ref('refs/heads/master^0');

	my $valid_head = verify_ref('HEAD^0');
	command_noisy(qw(update-ref refs/heads/master), $gs->refname);
	return if ($valid_head || !verify_ref('HEAD^0'));

	return if $ENV{GIT_DIR} !~ m#^(?:.*/)?\.git$#;
	my $index = $ENV{GIT_INDEX_FILE} || "$ENV{GIT_DIR}/index";
	return if -f $index;

	return if command_oneline(qw/rev-parse --is-inside-work-tree/) eq 'false';
	return if command_oneline(qw/rev-parse --is-inside-git-dir/) eq 'true';
	command_noisy(qw/read-tree -m -u -v HEAD HEAD/);
	print STDERR "Checked out HEAD:\n  ",
	             $gs->full_url, " r", $gs->last_rev, "\n";
}

sub complete_svn_url {
	my ($url, $path) = @_;
	$path =~ s#/+$##;
	if ($path !~ m#^[a-z\+]+://#) {
		if (!defined $url || $url !~ m#^[a-z\+]+://#) {
			fatal("E: '$path' is not a complete URL ",
			      "and a separate URL is not specified");
		}
		return ($url, $path);
	}
	return ($path, '');
}

sub complete_url_ls_init {
	my ($ra, $repo_path, $switch, $pfx) = @_;
	unless ($repo_path) {
		print STDERR "W: $switch not specified\n";
		return;
	}
	$repo_path =~ s#/+$##;
	if ($repo_path =~ m#^[a-z\+]+://#) {
		$ra = Git::SVN::Ra->new($repo_path);
		$repo_path = '';
	} else {
		$repo_path =~ s#^/+##;
		unless ($ra) {
			fatal("E: '$repo_path' is not a complete URL ",
			      "and a separate URL is not specified");
		}
	}
	my $url = $ra->{url};
	my $gs = Git::SVN->init($url, undef, undef, undef, 1);
	my $k = "svn-remote.$gs->{repo_id}.url";
	my $orig_url = eval { command_oneline(qw/config --get/, $k) };
	if ($orig_url && ($orig_url ne $gs->{url})) {
		die "$k already set: $orig_url\n",
		    "wanted to set to: $gs->{url}\n";
	}
	command_oneline('config', $k, $gs->{url}) unless $orig_url;
	my $remote_path = "$ra->{svn_path}/$repo_path";
	$remote_path =~ s#/+#/#g;
	$remote_path =~ s#^/##g;
	$remote_path .= "/*" if $remote_path !~ /\*/;
	my ($n) = ($switch =~ /^--(\w+)/);
	if (length $pfx && $pfx !~ m#/$#) {
		die "--prefix='$pfx' must have a trailing slash '/'\n";
	}
	command_noisy('config',
	              "svn-remote.$gs->{repo_id}.$n",
	              "$remote_path:refs/remotes/$pfx*" .
	                ('/*' x (($remote_path =~ tr/*/*/) - 1)) );
}

sub verify_ref {
	my ($ref) = @_;
	eval { command_oneline([ 'rev-parse', '--verify', $ref ],
	                       { STDERR => 0 }); };
}

sub get_tree_from_treeish {
	my ($treeish) = @_;
	# $treeish can be a symbolic ref, too:
	my $type = command_oneline(qw/cat-file -t/, $treeish);
	my $expected;
	while ($type eq 'tag') {
		($treeish, $type) = command(qw/cat-file tag/, $treeish);
	}
	if ($type eq 'commit') {
		$expected = (grep /^tree /, command(qw/cat-file commit/,
		                                    $treeish))[0];
		($expected) = ($expected =~ /^tree ($sha1)$/o);
		die "Unable to get tree from $treeish\n" unless $expected;
	} elsif ($type eq 'tree') {
		$expected = $treeish;
	} else {
		die "$treeish is a $type, expected tree, tag or commit\n";
	}
	return $expected;
}

sub get_commit_entry {
	my ($treeish) = shift;
	my %log_entry = ( log => '', tree => get_tree_from_treeish($treeish) );
	my $commit_editmsg = "$ENV{GIT_DIR}/COMMIT_EDITMSG";
	my $commit_msg = "$ENV{GIT_DIR}/COMMIT_MSG";
	open my $log_fh, '>', $commit_editmsg or croak $!;

	my $type = command_oneline(qw/cat-file -t/, $treeish);
	if ($type eq 'commit' || $type eq 'tag') {
		my ($msg_fh, $ctx) = command_output_pipe('cat-file',
		                                         $type, $treeish);
		my $in_msg = 0;
		my $author;
		my $saw_from = 0;
		my $msgbuf = "";
		while (<$msg_fh>) {
			if (!$in_msg) {
				$in_msg = 1 if (/^\s*$/);
				$author = $1 if (/^author (.*>)/);
			} elsif (/^git-svn-id: /) {
				# skip this for now, we regenerate the
				# correct one on re-fetch anyways
				# TODO: set *:merge properties or like...
			} else {
				if (/^From:/ || /^Signed-off-by:/) {
					$saw_from = 1;
				}
				$msgbuf .= $_;
			}
		}
		$msgbuf =~ s/\s+$//s;
		if ($Git::SVN::_add_author_from && defined($author)
		    && !$saw_from) {
			$msgbuf .= "\n\nFrom: $author";
		}
		print $log_fh $msgbuf or croak $!;
		command_close_pipe($msg_fh, $ctx);
	}
	close $log_fh or croak $!;

	if ($_edit || ($type eq 'tree')) {
		my $editor = $ENV{VISUAL} || $ENV{EDITOR} || 'vi';
		# TODO: strip out spaces, comments, like git-commit.sh
		system($editor, $commit_editmsg);
	}
	rename $commit_editmsg, $commit_msg or croak $!;
	{
		require Encode;
		# SVN requires messages to be UTF-8 when entering the repo
		local $/;
		open $log_fh, '<', $commit_msg or croak $!;
		binmode $log_fh;
		chomp($log_entry{log} = <$log_fh>);

		my $enc = Git::config('i18n.commitencoding') || 'UTF-8';
		my $msg = $log_entry{log};

		eval { $msg = Encode::decode($enc, $msg, 1) };
		if ($@) {
			die "Could not decode as $enc:\n", $msg,
			    "\nPerhaps you need to set i18n.commitencoding\n";
		}

		eval { $msg = Encode::encode('UTF-8', $msg, 1) };
		die "Could not encode as UTF-8:\n$msg\n" if $@;

		$log_entry{log} = $msg;

		close $log_fh or croak $!;
	}
	unlink $commit_msg;
	\%log_entry;
}

sub s_to_file {
	my ($str, $file, $mode) = @_;
	open my $fd,'>',$file or croak $!;
	print $fd $str,"\n" or croak $!;
	close $fd or croak $!;
	chmod ($mode &~ umask, $file) if (defined $mode);
}

sub file_to_s {
	my $file = shift;
	open my $fd,'<',$file or croak "$!: file: $file\n";
	local $/;
	my $ret = <$fd>;
	close $fd or croak $!;
	$ret =~ s/\s*$//s;
	return $ret;
}

# '<svn username> = real-name <email address>' mapping based on git-svnimport:
sub load_authors {
	open my $authors, '<', $_authors or die "Can't open $_authors $!\n";
	my $log = $cmd eq 'log';
	while (<$authors>) {
		chomp;
		next unless /^(.+?|\(no author\))\s*=\s*(.+?)\s*<(.+)>\s*$/;
		my ($user, $name, $email) = ($1, $2, $3);
		if ($log) {
			$Git::SVN::Log::rusers{"$name <$email>"} = $user;
		} else {
			$users{$user} = [$name, $email];
		}
	}
	close $authors or croak $!;
}

# convert GetOpt::Long specs for use by git-config
sub read_repo_config {
	return unless -d $ENV{GIT_DIR};
	my $opts = shift;
	my @config_only;
	foreach my $o (keys %$opts) {
		# if we have mixedCase and a long option-only, then
		# it's a config-only variable that we don't need for
		# the command-line.
		push @config_only, $o if ($o =~ /[A-Z]/ && $o =~ /^[a-z]+$/i);
		my $v = $opts->{$o};
		my ($key) = ($o =~ /^([a-zA-Z\-]+)/);
		$key =~ s/-//g;
		my $arg = 'git config';
		$arg .= ' --int' if ($o =~ /[:=]i$/);
		$arg .= ' --bool' if ($o !~ /[:=][sfi]$/);
		if (ref $v eq 'ARRAY') {
			chomp(my @tmp = `$arg --get-all svn.$key`);
			@$v = @tmp if @tmp;
		} else {
			chomp(my $tmp = `$arg --get svn.$key`);
			if ($tmp && !($arg =~ / --bool/ && $tmp eq 'false')) {
				$$v = $tmp;
			}
		}
	}
	delete @$opts{@config_only} if @config_only;
}

sub extract_metadata {
	my $id = shift or return (undef, undef, undef);
	my ($url, $rev, $uuid) = ($id =~ /^\s*git-svn-id:\s+(.*)\@(\d+)
							\s([a-f\d\-]+)$/x);
	if (!defined $rev || !$uuid || !$url) {
		# some of the original repositories I made had
		# identifiers like this:
		($rev, $uuid) = ($id =~/^\s*git-svn-id:\s(\d+)\@([a-f\d\-]+)/);
	}
	return ($url, $rev, $uuid);
}

sub cmt_metadata {
	return extract_metadata((grep(/^git-svn-id: /,
		command(qw/cat-file commit/, shift)))[-1]);
}

sub cmt_sha2rev_batch {
	my %s2r;
	my ($pid, $in, $out, $ctx) = command_bidi_pipe(qw/cat-file --batch/);
	my $list = shift;

	foreach my $sha (@{$list}) {
		my $first = 1;
		my $size = 0;
		print $out $sha, "\n";

		while (my $line = <$in>) {
			if ($first && $line =~ /^[[:xdigit:]]{40}\smissing$/) {
				last;
			} elsif ($first &&
			       $line =~ /^[[:xdigit:]]{40}\scommit\s(\d+)$/) {
				$first = 0;
				$size = $1;
				next;
			} elsif ($line =~ /^(git-svn-id: )/) {
				my (undef, $rev, undef) =
				                      extract_metadata($line);
				$s2r{$sha} = $rev;
			}

			$size -= length($line);
			last if ($size == 0);
		}
	}

	command_close_bidi_pipe($pid, $in, $out, $ctx);

	return \%s2r;
}

sub working_head_info {
	my ($head, $refs) = @_;
	my @args = ('log', '--no-color', '--first-parent', '--pretty=medium');
	my ($fh, $ctx) = command_output_pipe(@args, $head);
	my $hash;
	my %max;
	while (<$fh>) {
		if ( m{^commit ($::sha1)$} ) {
			unshift @$refs, $hash if $hash and $refs;
			$hash = $1;
			next;
		}
		next unless s{^\s*(git-svn-id:)}{$1};
		my ($url, $rev, $uuid) = extract_metadata($_);
		if (defined $url && defined $rev) {
			next if $max{$url} and $max{$url} < $rev;
			if (my $gs = Git::SVN->find_by_url($url)) {
				my $c = $gs->rev_map_get($rev, $uuid);
				if ($c && $c eq $hash) {
					close $fh; # break the pipe
					return ($url, $rev, $uuid, $gs);
				} else {
					$max{$url} ||= $gs->rev_map_max;
				}
			}
		}
	}
	command_close_pipe($fh, $ctx);
	(undef, undef, undef, undef);
}

sub read_commit_parents {
	my ($parents, $c) = @_;
	chomp(my $p = command_oneline(qw/rev-list --parents -1/, $c));
	$p =~ s/^($c)\s*// or die "rev-list --parents -1 $c failed!\n";
	@{$parents->{$c}} = split(/ /, $p);
}

sub linearize_history {
	my ($gs, $refs) = @_;
	my %parents;
	foreach my $c (@$refs) {
		read_commit_parents(\%parents, $c);
	}

	my @linear_refs;
	my %skip = ();
	my $last_svn_commit = $gs->last_commit;
	foreach my $c (reverse @$refs) {
		next if $c eq $last_svn_commit;
		last if $skip{$c};

		unshift @linear_refs, $c;
		$skip{$c} = 1;

		# we only want the first parent to diff against for linear
		# history, we save the rest to inject when we finalize the
		# svn commit
		my $fp_a = verify_ref("$c~1");
		my $fp_b = shift @{$parents{$c}} if $parents{$c};
		if (!$fp_a || !$fp_b) {
			die "Commit $c\n",
			    "has no parent commit, and therefore ",
			    "nothing to diff against.\n",
			    "You should be working from a repository ",
			    "originally created by git-svn\n";
		}
		if ($fp_a ne $fp_b) {
			die "$c~1 = $fp_a, however parsing commit $c ",
			    "revealed that:\n$c~1 = $fp_b\nBUG!\n";
		}

		foreach my $p (@{$parents{$c}}) {
			$skip{$p} = 1;
		}
	}
	(\@linear_refs, \%parents);
}

sub find_file_type_and_diff_status {
	my ($path) = @_;
	return ('dir', '') if $path eq '';

	my $diff_output =
	    command_oneline(qw(diff --cached --name-status --), $path) || "";
	my $diff_status = (split(' ', $diff_output))[0] || "";

	my $ls_tree = command_oneline(qw(ls-tree HEAD), $path) || "";

	return (undef, undef) if !$diff_status && !$ls_tree;

	if ($diff_status eq "A") {
		return ("link", $diff_status) if -l $path;
		return ("dir", $diff_status) if -d $path;
		return ("file", $diff_status);
	}

	my $mode = (split(' ', $ls_tree))[0] || "";

	return ("link", $diff_status) if $mode eq "120000";
	return ("dir", $diff_status) if $mode eq "040000";
	return ("file", $diff_status);
}

sub md5sum {
	my $arg = shift;
	my $ref = ref $arg;
	my $md5 = Digest::MD5->new();
        if ($ref eq 'GLOB' || $ref eq 'IO::File' || $ref eq 'File::Temp') {
		$md5->addfile($arg) or croak $!;
	} elsif ($ref eq 'SCALAR') {
		$md5->add($$arg) or croak $!;
	} elsif (!$ref) {
		$md5->add($arg) or croak $!;
	} else {
		::fatal "Can't provide MD5 hash for unknown ref type: '", $ref, "'";
	}
	return $md5->hexdigest();
}

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;

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 = $glob_spec->{path};
	foreach (command(qw#for-each-ref --format=%(refname) refs/remotes#)) {
		next unless m#^refs/remotes/$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 $refname) {
				die "Refspec conflict:\n",
				    "existing: refs/remotes/$existing\n",
				    " globbed: refs/remotes/$refname\n";
			}
			my $u = (::cmt_metadata("refs/remotes/$refname"))[0];
			$u =~ s!^\Q$url\E(/|$)!! or die
			  "refs/remotes/$refname: '$url' not found in '$u'\n";
			if ($pathname ne $u) {
				warn "W: Refspec glob conflict ",
				     "(ref: refs/remotes/$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;
	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 $use_svm_props;
	foreach (grep { s/^svn-remote\.// } command(qw/config -l/)) {
		if (m!^(.+)\.fetch=\s*(.*)\s*:\s*(.+)\s*$!) {
			my ($remote, $local_ref, $_remote_ref) = ($1, $2, $3);
			die("svn-remote.$remote: remote ref '$_remote_ref' "
			    . "must start with 'refs/remotes/'\n")
				unless $_remote_ref =~ m{^refs/remotes/(.+)};
			my $remote_ref = $1;
			$local_ref =~ s{^/}{};
			$r->{$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} = $2;
		} elsif (m!^(.+)\.(branches|tags)=
		           (.*):refs/remotes/(.+)\s*$/!x) {
			my ($p, $g) = ($3, $4);
			my $rs = $r->{$1}->{$2} = {
			                  t => $2,
					  remote => $1,
			                  path => Git::SVN::GlobSpec->new($p),
			                  ref => Git::SVN::GlobSpec->new($g) };
			if (length($rs->{ref}->{right}) != 0) {
				die "The '*' glob character must be the last ",
				    "character of '$g'\n";
			}
		}
	}

	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;

	$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 (defined $xpath) {
		die "svn-remote.$xrepo_id.fetch already set to track ",
		    "$xpath:refs/remotes/", $self->refname, "\n";
	}
	unless ($no_write) {
		command_noisy('config',
			      "svn-remote.$self->{repo_id}.url", $url);
		$self->{path} =~ s{^/}{};
		command_noisy('config', '--add',
			      "svn-remote.$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 (qw/branches tags/) {
			resolve_local_globs($u, $fetch,
			                    $remotes->{$repo_id}->{$_});
		}
		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 ($ref_id) = @_;
	foreach (command(qw/config -l/)) {
		next unless m!^svn-remote\.(.+)\.fetch=
		              \s*(.*)\s*:\s*refs/remotes/(.+)\s*$!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 $repo_id) {
			die "Could not find a \"svn-remote.*.fetch\" key ",
			    "in the repository configuration matching: ",
			    "refs/remotes/$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",
		                            ":refs/remotes/$ref_id\$") or
		     die "Failed to read \"svn-remote.$repo_id.fetch\" ",
		         "\":refs/remotes/$ref_id\$\" in config\n";
		($self->{path}, undef) = split(/\s*:\s*/, $fetch);
	}
	$self->{url} = command_oneline('config', '--get',
	                               "svn-remote.$repo_id.url") or
                  die "Failed to read \"svn-remote.$repo_id.url\" in config\n";
	$self->rebuild;
	$self;
}

sub refname {
	my ($refname) = "refs/remotes/$_[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;

	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);

		$uuid =~ m{^[0-9a-f\-]{30,}$}
		    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";
	}

	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,})$}) or
		   die "doesn't look right - svn:sync-from-uuid is '$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) = ($uuid =~ m{^([0-9a-f\-]{30,})$}) 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 && $uuid =~ /^([a-f\d\-]{30,})$/) {
			$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;
}

sub rel_path {
	my ($self) = @_;
	my $repos_root = $self->ra->{repos_root};
	return $self->{path} if ($self->{url} eq $repos_root);
	my $url = $self->{url} .
	          (length $self->{path} ? "/$self->{path}" : $self->{path});
	$url =~ s!^\Q$repos_root\E(?:/+|$)!!g;
	$url;
}

# 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, $p;
		# MAXPARENT is defined to 16 in commit-tree.c:
		last if @ret >= 16;
	}
	if (@tmp) {
		die "r$log_entry->{revision}: No room for parents:\n\t",
		    join("\n\t", @tmp), "\n";
	}
	@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 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 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;
	}
	my $repos_root = $self->ra->{repos_root};
	my $extended_path = $self->{url} . '/' . $self->{path};
	$extended_path =~ s#^\Q$repos_root\E(/|$)##;
	$self->{path_regex} ||= qr/^\/\Q$extended_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 {
		                   $paths =
				      Git::SVN::Ra::dup_changed_paths($_[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->rel_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 = $repos_root . $branch_from;
	print STDERR  "Found possible branch point: ",
	              "$new_url => ", $self->full_url, ", $r\n";
	$branch_from =~ s#^/##;
	my $gs = $self->other_gs($new_url, $url, $repos_root,
		                 $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";
		my $ed;
		if ($self->ra->can_do_switch) {
			$self->assert_index_clean($parent);
			print STDERR "Following parent with do_switch\n";
			# 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;
			$ed = SVN::Git::Fetcher->new($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";
			$self->tmp_index_do(sub {
			    command_noisy('read-tree', $parent);
			});
			$self->{last_commit} = $parent;
		} else {
			print STDERR "Following parent with do_update\n";
			$ed = SVN::Git::Fetcher->new($self);
			$self->ra->gs_do_update($rev, $rev, $self, $ed)
			  or die "SVN connection failed somewhere...\n";
		}
		print STDERR "Successfully followed parent\n";
		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;
		}
		$ed = SVN::Git::Fetcher->new($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;
		}
		$ed = SVN::Git::Fetcher->new($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 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;
}

# 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 =
		    POSIX::strftime('%Z', $S, $M, $H, $d, $m - 1, $Y - 1900);

		# 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, $repos_root,
	    $branch_from, $r, $old_ref_id) = @_;
	my $gs = Git::SVN->find_by_url($new_url, $repos_root, $branch_from);
	unless ($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);
		print STDERR "Initializing parent: $ref_id\n";
		my ($u, $p, $repo_id) = ($new_url, '', $ref_id);
		if ($u =~ s#^\Q$url\E(/|$)##) {
			$p = $u;
			$u = $url;
			$repo_id = $self->{repo_id};
		}
		$gs = Git::SVN->init($u, $p, $repo_id, $ref_id, 1);
	}
	$gs
}

sub call_authors_prog {
	my ($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 make_log_entry {
	my ($self, $rev, $parents, $ed) = @_;
	my $untracked = $self->get_untracked($ed);

	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";
		}
		my ($uuid, $r) = $headrev =~ m{^([a-f\d\-]{30,}):(\d+)$};
		# 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);
		$log_entry{metadata} = "$url\@$rev " .
		                       $self->ra->get_uuid;
		$email ||= "$author\@" . $self->ra->get_uuid;
		$commit_email ||= "$author\@" . $self->ra->get_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 => $self->{path} );
	if (!SVN::Git::Editor->new(\%ed_opts)->apply_diff) {
		print "No changes\nr$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, $ctx) =
	    command_output_pipe(qw/rev-list --pretty=raw --no-color --reverse/,
				($head ? "$head.." : "") . $self->refname,
				'--');
	my $metadata_url = $self->metadata_url;
	remove_username($metadata_url);
	my $svn_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) = @_;
	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 $sig;
	$update_ref ||= 0;
	if ($update_ref) {
		$SIG{INT} = $SIG{HUP} = $SIG{TERM} = $SIG{ALRM} = $SIG{PIPE} =
		            $SIG{USR1} = $SIG{USR2} = sub { $sig = $_[0] };
	}
	mkfile($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) {
		$SIG{INT} = $SIG{HUP} = $SIG{TERM} = $SIG{ALRM} = $SIG{PIPE} =
		            $SIG{USR1} = $SIG{USR2} = 'DEFAULT';
		kill $sig, $$ if defined $sig;
	}
}

# 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('NH40', $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 = $Git::SVN::default_repo_id;
	}
	unless (defined $ref_id && length $ref_id) {
		$_[2] = $ref_id = $Git::SVN::default_ref_id;
	}
	$_[1] = $repo_id;
	my $dir = "$ENV{GIT_DIR}/svn/$ref_id";
	$_[3] = $path = '' unless (defined $path);
	mkpath(["$ENV{GIT_DIR}/svn"]);
	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 remove_username {
	$_[0] =~ s{^([^:]*://)[^@]+@}{$1};
}

package Git::SVN::Prompt;
use strict;
use warnings;
require SVN::Core;
use vars qw/$_no_auth_cache $_username/;

sub simple {
	my ($cred, $realm, $default_username, $may_save, $pool) = @_;
	$may_save = undef if $_no_auth_cache;
	$default_username = $_username if defined $_username;
	if (defined $default_username && length $default_username) {
		if (defined $realm && length $realm) {
			print STDERR "Authentication realm: $realm\n";
			STDERR->flush;
		}
		$cred->username($default_username);
	} else {
		username($cred, $realm, $may_save, $pool);
	}
	$cred->password(_read_password("Password for '" .
	                               $cred->username . "': ", $realm));
	$cred->may_save($may_save);
	$SVN::_Core::SVN_NO_ERROR;
}

sub ssl_server_trust {
	my ($cred, $realm, $failures, $cert_info, $may_save, $pool) = @_;
	$may_save = undef if $_no_auth_cache;
	print STDERR "Error validating server certificate for '$realm':\n";
	{
		no warnings 'once';
		# All variables SVN::Auth::SSL::* are used only once,
		# so we're shutting up Perl warnings about this.
		if ($failures & $SVN::Auth::SSL::UNKNOWNCA) {
			print STDERR " - The certificate is not issued ",
			    "by a trusted authority. Use the\n",
			    "   fingerprint to validate ",
			    "the certificate manually!\n";
		}
		if ($failures & $SVN::Auth::SSL::CNMISMATCH) {
			print STDERR " - The certificate hostname ",
			    "does not match.\n";
		}
		if ($failures & $SVN::Auth::SSL::NOTYETVALID) {
			print STDERR " - The certificate is not yet valid.\n";
		}
		if ($failures & $SVN::Auth::SSL::EXPIRED) {
			print STDERR " - The certificate has expired.\n";
		}
		if ($failures & $SVN::Auth::SSL::OTHER) {
			print STDERR " - The certificate has ",
			    "an unknown error.\n";
		}
	} # no warnings 'once'
	printf STDERR
	        "Certificate information:\n".
	        " - Hostname: %s\n".
	        " - Valid: from %s until %s\n".
	        " - Issuer: %s\n".
	        " - Fingerprint: %s\n",
	        map $cert_info->$_, qw(hostname valid_from valid_until
	                               issuer_dname fingerprint);
	my $choice;
prompt:
	print STDERR $may_save ?
	      "(R)eject, accept (t)emporarily or accept (p)ermanently? " :
	      "(R)eject or accept (t)emporarily? ";
	STDERR->flush;
	$choice = lc(substr(<STDIN> || 'R', 0, 1));
	if ($choice =~ /^t$/i) {
		$cred->may_save(undef);
	} elsif ($choice =~ /^r$/i) {
		return -1;
	} elsif ($may_save && $choice =~ /^p$/i) {
		$cred->may_save($may_save);
	} else {
		goto prompt;
	}
	$cred->accepted_failures($failures);
	$SVN::_Core::SVN_NO_ERROR;
}

sub ssl_client_cert {
	my ($cred, $realm, $may_save, $pool) = @_;
	$may_save = undef if $_no_auth_cache;
	print STDERR "Client certificate filename: ";
	STDERR->flush;
	chomp(my $filename = <STDIN>);
	$cred->cert_file($filename);
	$cred->may_save($may_save);
	$SVN::_Core::SVN_NO_ERROR;
}

sub ssl_client_cert_pw {
	my ($cred, $realm, $may_save, $pool) = @_;
	$may_save = undef if $_no_auth_cache;
	$cred->password(_read_password("Password: ", $realm));
	$cred->may_save($may_save);
	$SVN::_Core::SVN_NO_ERROR;
}

sub username {
	my ($cred, $realm, $may_save, $pool) = @_;
	$may_save = undef if $_no_auth_cache;
	if (defined $realm && length $realm) {
		print STDERR "Authentication realm: $realm\n";
	}
	my $username;
	if (defined $_username) {
		$username = $_username;
	} else {
		print STDERR "Username: ";
		STDERR->flush;
		chomp($username = <STDIN>);
	}
	$cred->username($username);
	$cred->may_save($may_save);
	$SVN::_Core::SVN_NO_ERROR;
}

sub _read_password {
	my ($prompt, $realm) = @_;
	print STDERR $prompt;
	STDERR->flush;
	require Term::ReadKey;
	Term::ReadKey::ReadMode('noecho');
	my $password = '';
	while (defined(my $key = Term::ReadKey::ReadKey(0))) {
		last if $key =~ /[\012\015]/; # \n\r
		$password .= $key;
	}
	Term::ReadKey::ReadMode('restore');
	print STDERR "\n";
	STDERR->flush;
	$password;
}

package SVN::Git::Fetcher;
use vars qw/@ISA/;
use strict;
use warnings;
use Carp qw/croak/;
use File::Temp qw/tempfile/;
use IO::File qw//;
use vars qw/$_ignore_regex/;

# file baton members: path, mode_a, mode_b, pool, fh, blob, base
sub new {
	my ($class, $git_svn, $switch_path) = @_;
	my $self = SVN::Delta::Editor->new;
	bless $self, $class;
	if (exists $git_svn->{last_commit}) {
		$self->{c} = $git_svn->{last_commit};
		$self->{empty_symlinks} =
		                  _mark_empty_symlinks($git_svn, $switch_path);
	}
	$self->{ignore_regex} = eval { command_oneline('config', '--get',
			     "svn-remote.$git_svn->{repo_id}.ignore-paths") };
	$self->{empty} = {};
	$self->{dir_prop} = {};
	$self->{file_prop} = {};
	$self->{absent_dir} = {};
	$self->{absent_file} = {};
	$self->{gii} = $git_svn->tmp_index_do(sub { Git::IndexInfo->new });
	$self;
}

# this uses the Ra object, so it must be called before do_{switch,update},
# not inside them (when the Git::SVN::Fetcher object is passed) to
# do_{switch,update}
sub _mark_empty_symlinks {
	my ($git_svn, $switch_path) = @_;
	my $bool = Git::config_bool('svn.brokenSymlinkWorkaround');
	return {} if (!defined($bool)) || (defined($bool) && ! $bool);

	my %ret;
	my ($rev, $cmt) = $git_svn->last_rev_commit;
	return {} unless ($rev && $cmt);

	# allow the warning to be printed for each revision we fetch to
	# ensure the user sees it.  The user can also disable the workaround
	# on the repository even while git svn is running and the next
	# revision fetched will skip this expensive function.
	my $printed_warning;
	chomp(my $empty_blob = `git hash-object -t blob --stdin < /dev/null`);
	my ($ls, $ctx) = command_output_pipe(qw/ls-tree -r -z/, $cmt);
	local $/ = "\0";
	my $pfx = defined($switch_path) ? $switch_path : $git_svn->{path};
	$pfx .= '/' if length($pfx);
	while (<$ls>) {
		chomp;
		s/\A100644 blob $empty_blob\t//o or next;
		unless ($printed_warning) {
			print STDERR "Scanning for empty symlinks, ",
			             "this may take a while if you have ",
				     "many empty files\n",
				     "You may disable this with `",
				     "git config svn.brokenSymlinkWorkaround ",
				     "false'.\n",
				     "This may be done in a different ",
				     "terminal without restarting ",
				     "git svn\n";
			$printed_warning = 1;
		}
		my $path = $_;
		my (undef, $props) =
		               $git_svn->ra->get_file($pfx.$path, $rev, undef);
		if ($props->{'svn:special'}) {
			$ret{$path} = 1;
		}
	}
	command_close_pipe($ls, $ctx);
	\%ret;
}

# returns true if a given path is inside a ".git" directory
sub in_dot_git {
	$_[0] =~ m{(?:^|/)\.git(?:/|$)};
}

# return value: 0 -- don't ignore, 1 -- ignore