git-svn info: implement info command

Implement "git-svn info" for files and directories based on the
"svn info" command.  Note that the -r/--revision argument is not
supported yet.

Added 18 tests in t/t9119-git-svn-info.sh.

[ew: small fix to work without arguments on all working directories]

Signed-off-by: David D. Kilzer <ddkilzer@kilzer.net>
Acked-by: Eric Wong <normalperson@yhbt.net>
diff --git a/git-svn.perl b/git-svn.perl
index 98c980f..fd10361 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -178,6 +178,10 @@
 			  'file|F=s' => \$_file,
 			  'revision|r=s' => \$_revision,
 			%cmt_opts } ],
+	'info' => [ \&cmd_info,
+		    "Show info about the latest SVN revision
+		     on the current branch",
+		    { } ],
 );
 
 my $cmd;
@@ -586,12 +590,18 @@
 
 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;
 	return $path;
 }
 
@@ -743,6 +753,104 @@
 	}
 }
 
+sub cmd_info {
+	my $path = canonicalize_path(shift or ".");
+	unless (scalar(@_) == 0) {
+		die "Too many arguments specified\n";
+	}
+
+	my ($file_type, $diff_status) = find_file_type_and_diff_status($path);
+
+	if (!$file_type && !$diff_status) {
+		print STDERR "$path:  (Not a versioned resource)\n\n";
+		return;
+	}
+
+	my ($url, $rev, $uuid, $gs) = working_head_info('HEAD');
+	unless ($gs) {
+		die "Unable to determine upstream SVN information from ",
+		    "working tree history\n";
+	}
+	my $full_url = $url . ($path eq "." ? "" : "/$path");
+
+	my $result = "Path: $path\n";
+	$result .= "Name: " . basename($path) . "\n" if $file_type ne "dir";
+	$result .= "URL: " . $full_url . "\n";
+
+	my $repos_root = $gs->ra->{repos_root};
+	Git::SVN::remove_username($repos_root);
+	$result .= "Repository Root: $repos_root\n";
+	$result .= "Repository UUID: $uuid\n" unless $diff_status eq "A";
+	$result .= "Revision: " . ($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, "--", $path);
+	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 = Git::SVN::Util::md5sum("link $file_name");
+			} else {
+				$checksum = Git::SVN::Util::md5sum($fh);
+			}
+			command_close_pipe($fh, $ctx);
+		} elsif ($file_type eq "link") {
+			my $file_name =
+			    command(qw(cat-file blob), "HEAD:$path");
+			$checksum =
+			    Git::SVN::Util::md5sum("link " . $file_name);
+		} else {
+			open FILE, "<", $path or die $!;
+			$checksum = Git::SVN::Util::md5sum(\*FILE);
+			close FILE or die $!;
+		}
+		$result .= "Checksum: " . $checksum . "\n";
+	}
+
+	print $result, "\n";
+}
+
 ########################### utility functions #########################
 
 sub rebase_cmd {
@@ -1050,6 +1158,31 @@
 	(\@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);
+}
+
 package Git::SVN::Util;
 use strict;
 use warnings;