X-Git-Url: https://sipb.mit.edu/gitweb.cgi/ikiwiki.git/blobdiff_plain/ab712992930e190f421a769c52843fb83867404f..27c1595cec8606f44d2ec33989daca70cab7d22f:/IkiWiki.pm

diff --git a/IkiWiki.pm b/IkiWiki.pm
index 292f18f5e..7c35ce2b5 100644
--- a/IkiWiki.pm
+++ b/IkiWiki.pm
@@ -5,18 +5,22 @@ use warnings;
 use strict;
 use Encode;
 use HTML::Entities;
+use URI::Escape q{uri_escape_utf8};
+use POSIX;
 use open qw{:utf8 :std};
 
-use vars qw{%config %links %oldlinks %oldpagemtime %pagectime %pagecase
-            %renderedfiles %oldrenderedfiles %pagesources %depends %hooks
-	    %forcerebuild $gettext_obj};
+use vars qw{%config %links %oldlinks %pagemtime %pagectime %pagecase
+            %renderedfiles %oldrenderedfiles %pagesources %destsources
+	    %depends %hooks %forcerebuild $gettext_obj};
 
 use Exporter q{import};
 our @EXPORT = qw(hook debug error template htmlpage add_depends pagespec_match
                  bestlink htmllink readfile writefile pagetype srcfile pagename
-                 displaytime will_render gettext
-                 %config %links %renderedfiles %pagesources);
-our $VERSION = 1.01; # plugin interface version
+                 displaytime will_render gettext urlto targetpage
+                 %config %links %renderedfiles %pagesources %destsources);
+our $VERSION = 2.00; # plugin interface version, next is ikiwiki version
+our $version='unknown'; # VERSION_AUTOREPLACE done by Makefile, DNE
+my $installdir=''; # INSTALLDIR_AUTOREPLACE done by Makefile, DNE
 
 # Optimisation.
 use Memoize;
@@ -24,27 +28,41 @@ memoize("abs2rel");
 memoize("pagespec_translate");
 memoize("file_pruned");
 
-my $installdir=''; # INSTALLDIR_AUTOREPLACE done by Makefile, DNE
-our $version='unknown'; # VERSION_AUTOREPLACE done by Makefile, DNE
-
 sub defaultconfig () { #{{{
-	wiki_file_prune_regexps => [qr/\.\./, qr/^\./, qr/\/\./, qr/\.x?html?$/,
-		qr/(^|\/).svn\//, qr/.arch-ids\//, qr/{arch}\//],
-	wiki_link_regexp => qr/\[\[(?:([^\]\|]+)\|)?([^\s\]]+)\]\]/,
+	wiki_file_prune_regexps => [qr/\.\./, qr/^\./, qr/\/\./,
+		qr/\.x?html?$/, qr/\.ikiwiki-new$/,
+		qr/(^|\/).svn\//, qr/.arch-ids\//, qr/{arch}\//,
+		qr/\.dpkg-tmp$/],
+	wiki_link_regexp => qr{
+		\[\[			# beginning of link
+		(?:
+			([^\]\|]+)	# 1: link text
+			\|		# followed by '|'
+		)?			# optional
+
+		([^\s\]#]+)		# 2: page to link to
+		(?:
+			\#		# '#', beginning of anchor
+			([^\s\]]+)	# 3: anchor text
+		)?			# optional
+
+		\]\]			# end of link
+	}x,
 	wiki_file_regexp => qr/(^[-[:alnum:]_.:\/+]+$)/,
 	web_commit_regexp => qr/^web commit (by (.*?(?=: |$))|from (\d+\.\d+\.\d+\.\d+)):?(.*)/,
 	verbose => 0,
 	syslog => 0,
 	wikiname => "wiki",
 	default_pageext => "mdwn",
+	htmlext => "html",
 	cgi => 0,
+	post_commit => 0,
 	rcs => '',
 	notify => 0,
 	url => '',
 	cgiurl => '',
 	historyurl => '',
 	diffurl => '',
-	anonok => 0,
 	rss => 0,
 	atom => 0,
 	discussion => 1,
@@ -66,12 +84,17 @@ sub defaultconfig () { #{{{
 	setup => undef,
 	adminuser => undef,
 	adminemail => undef,
-	plugin => [qw{mdwn inline htmlscrubber passwordauth}],
+	plugin => [qw{mdwn inline htmlscrubber passwordauth openid signinedit
+	              lockedit conditional}],
+	libdir => undef,
 	timeformat => '%c',
 	locale => undef,
 	sslcookie => 0,
 	httpauth => 0,
 	userdir => "",
+	usedirs => 1,
+	numbacklinks => 10,
+	account_creation_password => "",
 } #}}}
    
 sub checkconfig () { #{{{
@@ -81,8 +104,6 @@ sub checkconfig () { #{{{
 		delete $ENV{LC_ALL};
 	}
 	if (defined $config{locale}) {
-		eval q{use POSIX};
-		error($@) if $@;
 		if (POSIX::setlocale(&POSIX::LC_ALL, $config{locale})) {
 			$ENV{LANG}=$config{locale};
 			$gettext_obj=undef;
@@ -107,7 +128,7 @@ sub checkconfig () { #{{{
 		unless exists $config{wikistatedir};
 	
 	if ($config{rcs}) {
-		eval qq{require IkiWiki::Rcs::$config{rcs}};
+		eval qq{use IkiWiki::Rcs::$config{rcs}};
 		if ($@) {
 			error("Failed to load RCS module IkiWiki::Rcs::$config{rcs}: $@");
 		}
@@ -120,8 +141,12 @@ sub checkconfig () { #{{{
 } #}}}
 
 sub loadplugins () { #{{{
+	if (defined $config{libdir}) {
+		unshift @INC, $config{libdir};
+	}
+
 	loadplugin($_) foreach @{$config{plugin}};
-	
+
 	run_hooks(getopt => sub { shift->() });
 	if (grep /^-/, @ARGV) {
 		print STDERR "Unknown option: $_\n"
@@ -135,21 +160,35 @@ sub loadplugin ($) { #{{{
 
 	return if grep { $_ eq $plugin} @{$config{disable_plugins}};
 
+	foreach my $dir ($config{libdir}, "$installdir/lib/ikiwiki") {
+		if (defined $dir && -x "$dir/plugins/$plugin") {
+			require IkiWiki::Plugin::external;
+			import IkiWiki::Plugin::external "$dir/plugins/$plugin";
+			return 1;
+		}
+	}
+
 	my $mod="IkiWiki::Plugin::".possibly_foolish_untaint($plugin);
 	eval qq{use $mod};
 	if ($@) {
 		error("Failed to load plugin $mod: $@");
 	}
+	return 1;
 } #}}}
 
-sub error ($) { #{{{
+sub error ($;$) { #{{{
+	my $message=shift;
+	my $cleaner=shift;
 	if ($config{cgi}) {
 		print "Content-type: text/html\n\n";
 		print misctemplate(gettext("Error"),
-			"<p>".gettext("Error").": @_</p>");
+			"<p>".gettext("Error").": $message</p>");
+	}
+	log_message('err' => $message) if $config{syslog};
+	if (defined $cleaner) {
+		$cleaner->();
 	}
-	log_message(error => @_);
-	exit(1);
+	die $message."\n";
 } #}}}
 
 sub debug ($) { #{{{
@@ -169,8 +208,8 @@ sub log_message ($$) { #{{{
 			$log_open=1;
 		}
 		eval {
-			Sys::Syslog::syslog($type, join(" ", @_));
-		}
+			Sys::Syslog::syslog($type, "[$config{wikiname}] %s", join(" ", @_));
+		};
 	}
 	elsif (! $config{cgi}) {
 		print "@_\n";
@@ -182,7 +221,7 @@ sub log_message ($$) { #{{{
 
 sub possibly_foolish_untaint ($) { #{{{
 	my $tainted=shift;
-	my ($untainted)=$tainted=~/(.*)/;
+	my ($untainted)=$tainted=~/(.*)/s;
 	return $untainted;
 } #}}}
 
@@ -218,10 +257,21 @@ sub pagename ($) { #{{{
 	return $page;
 } #}}}
 
-sub htmlpage ($) { #{{{
+sub targetpage ($$) { #{{{
 	my $page=shift;
+	my $ext=shift;
+	
+	if (! $config{usedirs} || $page =~ /^index$/ ) {
+		return $page.".".$ext;
+	} else {
+		return $page."/index.".$ext;
+	}
+} #}}}
 
-	return $page.".html";
+sub htmlpage ($) { #{{{
+	my $page=shift;
+	
+	return targetpage($page, $config{htmlext});
 } #}}}
 
 sub srcfile ($) { #{{{
@@ -229,12 +279,13 @@ sub srcfile ($) { #{{{
 
 	return "$config{srcdir}/$file" if -e "$config{srcdir}/$file";
 	return "$config{underlaydir}/$file" if -e "$config{underlaydir}/$file";
-	error("internal error: $file cannot be found");
+	error("internal error: $file cannot be found in $config{srcdir} or $config{underlaydir}");
 } #}}}
 
-sub readfile ($;$) { #{{{
+sub readfile ($;$$) { #{{{
 	my $file=shift;
 	my $binary=shift;
+	my $wantfd=shift;
 
 	if (-l $file) {
 		error("cannot read a symlink ($file)");
@@ -243,16 +294,18 @@ sub readfile ($;$) { #{{{
 	local $/=undef;
 	open (IN, $file) || error("failed to read $file: $!");
 	binmode(IN) if ($binary);
+	return \*IN if $wantfd;
 	my $ret=<IN>;
-	close IN;
+	close IN || error("failed to read $file: $!");
 	return $ret;
 } #}}}
 
-sub writefile ($$$;$) { #{{{
+sub writefile ($$$;$$) { #{{{
 	my $file=shift; # can include subdirs
 	my $destdir=shift; # directory to put file in
 	my $content=shift;
 	my $binary=shift;
+	my $writer=shift;
 	
 	my $test=$file;
 	while (length $test) {
@@ -261,8 +314,12 @@ sub writefile ($$$;$) { #{{{
 		}
 		$test=dirname($test);
 	}
+	my $newfile="$destdir/$file.ikiwiki-new";
+	if (-l $newfile) {
+		error("cannot write to a symlink ($newfile)");
+	}
 
-	my $dir=dirname("$destdir/$file");
+	my $dir=dirname($newfile);
 	if (! -d $dir) {
 		my $d="";
 		foreach my $s (split(m!/+!, $dir)) {
@@ -272,11 +329,19 @@ sub writefile ($$$;$) { #{{{
 			}
 		}
 	}
-	
-	open (OUT, ">$destdir/$file") || error("failed to write $destdir/$file: $!");
+
+	my $cleanup = sub { unlink($newfile) };
+	open (OUT, ">$newfile") || error("failed to write $newfile: $!", $cleanup);
 	binmode(OUT) if ($binary);
-	print OUT $content;
-	close OUT;
+	if ($writer) {
+		$writer->(\*OUT, $cleanup);
+	}
+	else {
+		print OUT $content or error("failed writing to $newfile: $!", $cleanup);
+	}
+	close OUT || error("failed saving $newfile: $!", $cleanup);
+	rename($newfile, "$destdir/$file") || 
+		error("failed renaming $newfile to $destdir/$file: $!", $cleanup);
 } #}}}
 
 my %cleared;
@@ -295,9 +360,13 @@ sub will_render ($$;$) { #{{{
 		$renderedfiles{$page}=[$dest, grep { $_ ne $dest } @{$renderedfiles{$page}}];
 	}
 	else {
+		foreach my $old (@{$renderedfiles{$page}}) {
+			delete $destsources{$old};
+		}
 		$renderedfiles{$page}=[$dest];
 		$cleared{$page}=1;
 	}
+	$destsources{$dest}=$page;
 } #}}}
 
 sub bestlink ($$) { #{{{
@@ -323,8 +392,14 @@ sub bestlink ($$) { #{{{
 		}
 	} while $cwd=~s!/?[^/]+$!!;
 
-	if (length $config{userdir} && exists $links{"$config{userdir}/".lc($link)}) {
-		return "$config{userdir}/".lc($link);
+	if (length $config{userdir}) {
+		my $l = "$config{userdir}/".lc($link);
+		if (exists $links{$l}) {
+			return $l;
+		}
+		elsif (exists $pagecase{lc $l}) {
+			return $pagecase{lc $l};
+		}
 	}
 
 	#print STDERR "warning: page $page, broken link: $link\n";
@@ -342,27 +417,32 @@ sub pagetitle ($;$) { #{{{
 	my $unescaped=shift;
 
 	if ($unescaped) {
-		$page=~s/__(\d+)__/chr($1)/eg;
+		$page=~s/(__(\d+)__|_)/$1 eq '_' ? ' ' : chr($2)/eg;
 	}
 	else {
-		$page=~s/__(\d+)__/&#$1;/g;
+		$page=~s/(__(\d+)__|_)/$1 eq '_' ? ' ' : "&#$2;"/eg;
 	}
-	$page=~y/_/ /;
 
 	return $page;
 } #}}}
 
 sub titlepage ($) { #{{{
 	my $title=shift;
-	$title=~y/ /_/;
-	$title=~s/([^-[:alnum:]_:+\/.])/"__".ord($1)."__"/eg;
+	$title=~s/([^-[:alnum:]:+\/.])/$1 eq ' ' ? '_' : "__".ord($1)."__"/eg;
 	return $title;
 } #}}}
 
+sub linkpage ($) { #{{{
+	my $link=shift;
+	$link=~s/([^-[:alnum:]:+\/._])/$1 eq ' ' ? '_' : "__".ord($1)."__"/eg;
+	return $link;
+} #}}}
+
 sub cgiurl (@) { #{{{
 	my %params=@_;
 
-	return $config{cgiurl}."?".join("&amp;", map "$_=$params{$_}", keys %params);
+	return $config{cgiurl}."?".
+		join("&amp;", map $_."=".uri_escape_utf8($params{$_}), keys %params);
 } #}}}
 
 sub baseurl (;$) { #{{{
@@ -370,6 +450,7 @@ sub baseurl (;$) { #{{{
 
 	return "$config{url}/" if ! defined $page;
 	
+	$page=htmlpage($page);
 	$page=~s/[^\/]+$//;
 	$page=~s/[^\/]+\//..\//g;
 	return $page;
@@ -391,51 +472,95 @@ sub abs2rel ($$) { #{{{
 sub displaytime ($) { #{{{
 	my $time=shift;
 
-	eval q{use POSIX};
-	error($@) if $@;
 	# strftime doesn't know about encodings, so make sure
 	# its output is properly treated as utf8
 	return decode_utf8(POSIX::strftime(
 			$config{timeformat}, localtime($time)));
 } #}}}
 
-sub htmllink ($$$;$$$) { #{{{
+sub beautify_url ($) { #{{{
+	my $url=shift;
+
+	$url =~ s!/index.$config{htmlext}$!/!;
+	$url =~ s!^$!./!; # Browsers don't like empty links...
+
+	return $url;
+} #}}}
+
+sub urlto ($$) { #{{{
+	my $to=shift;
+	my $from=shift;
+
+	if (! length $to) {
+		return beautify_url(baseurl($from));
+	}
+
+	if (! $destsources{$to}) {
+		$to=htmlpage($to);
+	}
+
+	my $link = abs2rel($to, dirname(htmlpage($from)));
+
+	return beautify_url($link);
+} #}}}
+
+sub htmllink ($$$;@) { #{{{
 	my $lpage=shift; # the page doing the linking
 	my $page=shift; # the page that will contain the link (different for inline)
 	my $link=shift;
-	my $noimageinline=shift; # don't turn links into inline html images
-	my $forcesubpage=shift; # force a link to a subpage
-	my $linktext=shift; # set to force the link text to something
+	my %opts=@_;
 
 	my $bestlink;
-	if (! $forcesubpage) {
+	if (! $opts{forcesubpage}) {
 		$bestlink=bestlink($lpage, $link);
 	}
 	else {
 		$bestlink="$lpage/".lc($link);
 	}
 
-	$linktext=pagetitle(basename($link)) unless defined $linktext;
+	my $linktext;
+	if (defined $opts{linktext}) {
+		$linktext=$opts{linktext};
+	}
+	else {
+		$linktext=pagetitle(basename($link));
+	}
 	
 	return "<span class=\"selflink\">$linktext</span>"
 		if length $bestlink && $page eq $bestlink;
 	
-	if (! grep { $_ eq $bestlink } map { @{$_} } values %renderedfiles) {
+	if (! $destsources{$bestlink}) {
 		$bestlink=htmlpage($bestlink);
-	}
-	if (! grep { $_ eq $bestlink } map { @{$_} } values %renderedfiles) {
-		return $linktext unless length $config{cgiurl};
-		return "<span><a href=\"".
-			cgiurl(do => "create", page => lc($link), from => $page).
-			"\">?</a>$linktext</span>"
+
+		if (! $destsources{$bestlink}) {
+			return $linktext unless length $config{cgiurl};
+			return "<span><a href=\"".
+				cgiurl(
+					do => "create",
+					page => pagetitle(lc($link), 1),
+					from => $lpage
+				).
+				"\">?</a>$linktext</span>"
+		}
 	}
 	
-	$bestlink=abs2rel($bestlink, dirname($page));
+	$bestlink=abs2rel($bestlink, dirname(htmlpage($page)));
+	$bestlink=beautify_url($bestlink);
 	
-	if (! $noimageinline && isinlinableimage($bestlink)) {
+	if (! $opts{noimageinline} && isinlinableimage($bestlink)) {
 		return "<img src=\"$bestlink\" alt=\"$linktext\" />";
 	}
-	return "<a href=\"$bestlink\">$linktext</a>";
+
+	if (defined $opts{anchor}) {
+		$bestlink.="#".$opts{anchor};
+	}
+
+	my @attrs;
+	if (defined $opts{rel}) {
+		push @attrs, ' rel="'.$opts{rel}.'"';
+	}
+
+	return "<a href=\"$bestlink\"@attrs>$linktext</a>";
 } #}}}
 
 sub htmlize ($$$) { #{{{
@@ -469,33 +594,56 @@ sub linkify ($$$) { #{{{
 	my $content=shift;
 
 	$content =~ s{(\\?)$config{wiki_link_regexp}}{
-		$2 ? ( $1 ? "[[$2|$3]]" : htmllink($lpage, $page, titlepage($3), 0, 0, pagetitle($2)))
-		   : ( $1 ? "[[$3]]" :    htmllink($lpage, $page, titlepage($3)))
+		defined $2
+			? ( $1 
+				? "[[$2|$3".($4 ? "#$4" : "")."]]" 
+				: htmllink($lpage, $page, linkpage($3),
+					anchor => $4, linktext => pagetitle($2)))
+			: ( $1 
+				? "[[$3".($4 ? "#$4" : "")."]]"
+				: htmllink($lpage, $page, linkpage($3),
+					anchor => $4))
 	}eg;
 	
 	return $content;
 } #}}}
 
 my %preprocessing;
-sub preprocess ($$$;$) { #{{{
+our $preprocess_preview=0;
+sub preprocess ($$$;$$) { #{{{
 	my $page=shift; # the page the data comes from
 	my $destpage=shift; # the page the data will appear in (different for inline)
 	my $content=shift;
 	my $scan=shift;
+	my $preview=shift;
+
+	# Using local because it needs to be set within any nested calls
+	# of this function.
+	local $preprocess_preview=$preview if defined $preview;
 
 	my $handle=sub {
 		my $escape=shift;
 		my $command=shift;
 		my $params=shift;
 		if (length $escape) {
-			return "[[$command $params]]";
+			return "\\[[$command $params]]";
 		}
 		elsif (exists $hooks{preprocess}{$command}) {
 			return "" if $scan && ! $hooks{preprocess}{$command}{scan};
 			# Note: preserve order of params, some plugins may
 			# consider it significant.
 			my @params;
-			while ($params =~ /(?:(\w+)=)?(?:"""(.*?)"""|"([^"]+)"|(\S+))(?:\s+|$)/sg) {
+			while ($params =~ m{
+				(?:(\w+)=)?		# 1: named parameter key?
+				(?:
+					"""(.*?)"""	# 2: triple-quoted value
+				|
+					"([^"]+)"	# 3: single-quoted value
+				|
+					(\S+)		# 4: unquoted value
+				)
+				(?:\s+|$)		# delimiter to next param
+			}sgx) {
 				my $key=$1;
 				my $val;
 				if (defined $2) {
@@ -533,25 +681,48 @@ sub preprocess ($$$;$) { #{{{
 				@params,
 				page => $page,
 				destpage => $destpage,
+				preview => $preprocess_preview,
 			);
 			$preprocessing{$page}--;
 			return $ret;
 		}
 		else {
-			return "[[$command $params]]";
+			return "\\[[$command $params]]";
 		}
 	};
 	
-	$content =~ s{(\\?)\[\[(\w+)\s+((?:(?:\w+=)?(?:""".*?"""|"[^"]+"|[^\s\]]+)\s*)*)\]\]}{$handle->($1, $2, $3)}seg;
+	$content =~ s{
+		(\\?)		# 1: escape?
+		\[\[		# directive open
+		(\w+)		# 2: command
+		\s+
+		(		# 3: the parameters..
+			(?:
+				(?:\w+=)?		# named parameter key?
+				(?:
+					""".*?"""	# triple-quoted value
+					|
+					"[^"]+"		# single-quoted value
+					|
+					[^\s\]]+	# unquoted value
+				)
+				\s*			# whitespace or end
+							# of directive
+			)
+		*)		# 0 or more parameters
+		\]\]		# directive closed
+	}{$handle->($1, $2, $3)}sexg;
 	return $content;
 } #}}}
 
-sub filter ($$) { #{{{
+sub filter ($$$) { #{{{
 	my $page=shift;
+	my $destpage=shift;
 	my $content=shift;
 
 	run_hooks(filter => sub {
-		$content=shift->(page => $page, content => $content);
+		$content=shift->(page => $page, destpage => $destpage, 
+			content => $content);
 	});
 
 	return $content;
@@ -561,7 +732,8 @@ sub indexlink () { #{{{
 	return "<a href=\"$config{url}\">$config{wikiname}</a>";
 } #}}}
 
-sub lockwiki () { #{{{
+sub lockwiki (;$) { #{{{
+	my $wait=@_ ? shift : 1;
 	# Take an exclusive lock on the wiki to prevent multiple concurrent
 	# run issues. The lock will be dropped on program exit.
 	if (! -d $config{wikistatedir}) {
@@ -569,22 +741,51 @@ sub lockwiki () { #{{{
 	}
 	open(WIKILOCK, ">$config{wikistatedir}/lockfile") ||
 		error ("cannot write to $config{wikistatedir}/lockfile: $!");
-	if (! flock(WIKILOCK, 2 | 4)) {
-		debug("wiki seems to be locked, waiting for lock");
-		my $wait=600; # arbitrary, but don't hang forever to 
-		              # prevent process pileup
-		for (1..600) {
-			return if flock(WIKILOCK, 2 | 4);
-			sleep 1;
+	if (! flock(WIKILOCK, 2 | 4)) { # LOCK_EX | LOCK_NB
+		if ($wait) {
+			debug("wiki seems to be locked, waiting for lock");
+			my $wait=600; # arbitrary, but don't hang forever to 
+			              # prevent process pileup
+			for (1..$wait) {
+				return if flock(WIKILOCK, 2 | 4);
+				sleep 1;
+			}
+			error("wiki is locked; waited $wait seconds without lock being freed (possible stuck process or stale lock?)");
+		}
+		else {
+			return 0;
 		}
-		error("wiki is locked; waited $wait seconds without lock being freed (possible stuck process or stale lock?)");
 	}
+	return 1;
 } #}}}
 
 sub unlockwiki () { #{{{
 	close WIKILOCK;
 } #}}}
 
+sub commit_hook_enabled () { #{{{
+	open(COMMITLOCK, "+>$config{wikistatedir}/commitlock") ||
+		error ("cannot write to $config{wikistatedir}/commitlock: $!");
+	if (! flock(COMMITLOCK, 1 | 4)) { # LOCK_SH | LOCK_NB to test
+		close COMMITLOCK;
+		return 0;
+	}
+	close COMMITLOCK;
+	return 1;
+} #}}}
+
+sub disable_commit_hook () { #{{{
+	open(COMMITLOCK, ">$config{wikistatedir}/commitlock") ||
+		error ("cannot write to $config{wikistatedir}/commitlock: $!");
+	if (! flock(COMMITLOCK, 2)) { # LOCK_EX
+		error("failed to get commit lock");
+	}
+} #}}}
+
+sub enable_commit_hook () { #{{{
+	close COMMITLOCK;
+} #}}}
+
 sub loadindex () { #{{{
 	open (IN, "$config{wikistatedir}/index") || return;
 	while (<IN>) {
@@ -603,14 +804,15 @@ sub loadindex () { #{{{
 		my $page=pagename($items{src}[0]);
 		if (! $config{rebuild}) {
 			$pagesources{$page}=$items{src}[0];
-			$oldpagemtime{$page}=$items{mtime}[0];
+			$pagemtime{$page}=$items{mtime}[0];
 			$oldlinks{$page}=[@{$items{link}}];
 			$links{$page}=[@{$items{link}}];
 			$depends{$page}=$items{depends}[0] if exists $items{depends};
+			$destsources{$_}=$page foreach @{$items{dest}};
 			$renderedfiles{$page}=[@{$items{dest}}];
-			$oldrenderedfiles{$page}=[@{$items{dest}}];
 			$pagecase{lc $page}=$page;
 		}
+		$oldrenderedfiles{$page}=[@{$items{dest}}];
 		$pagectime{$page}=$items{ctime}[0];
 	}
 	close IN;
@@ -622,11 +824,12 @@ sub saveindex () { #{{{
 	if (! -d $config{wikistatedir}) {
 		mkdir($config{wikistatedir});
 	}
-	open (OUT, ">$config{wikistatedir}/index") || 
-		error("cannot write to $config{wikistatedir}/index: $!");
-	foreach my $page (keys %oldpagemtime) {
-		next unless $oldpagemtime{$page};
-		my $line="mtime=$oldpagemtime{$page} ".
+	my $newfile="$config{wikistatedir}/index.new";
+	my $cleanup = sub { unlink($newfile) };
+	open (OUT, ">$newfile") || error("cannot write to $newfile: $!", $cleanup);
+	foreach my $page (keys %pagemtime) {
+		next unless $pagemtime{$page};
+		my $line="mtime=$pagemtime{$page} ".
 			"ctime=$pagectime{$page} ".
 			"src=$pagesources{$page}";
 		$line.=" dest=$_" foreach @{$renderedfiles{$page}};
@@ -635,9 +838,11 @@ sub saveindex () { #{{{
 		if (exists $depends{$page}) {
 			$line.=" depends=".encode_entities($depends{$page}, " \t\n");
 		}
-		print OUT $line."\n";
+		print OUT $line."\n" || error("failed writing to $newfile: $!", $cleanup);
 	}
-	close OUT;
+	close OUT || error("failed saving to $newfile: $!", $cleanup);
+	rename($newfile, "$config{wikistatedir}/index") ||
+		error("failed renaming $newfile to $config{wikistatedir}/index", $cleanup);
 } #}}}
 
 sub template_file ($) { #{{{
@@ -657,7 +862,6 @@ sub template_params (@) { #{{{
 		return "";
 	}
 
-	require HTML::Template;
 	my @ret=(
 		filter => sub {
 			my $text_ref = shift;
@@ -672,6 +876,7 @@ sub template_params (@) { #{{{
 } #}}}
 
 sub template ($;@) { #{{{
+	require HTML::Template;
 	HTML::Template->new(template_params(@_));
 } #}}}
 
@@ -836,7 +1041,21 @@ sub pagespec_translate ($) { #{{{
 
 	# Convert spec to perl code.
 	my $code="";
-	while ($spec=~m/\s*(\!|\(|\)|\w+\([^\)]+\)|[^\s()]+)\s*/ig) {
+	while ($spec=~m{
+		\s*		# ignore whitespace
+		(		# 1: match a single word
+			\!		# !
+		|
+			\(		# (
+		|
+			\)		# )
+		|
+			\w+\([^\)]*\)	# command(params)
+		|
+			[^\s()]+	# any other text
+		)
+		\s*		# ignore whitespace
+	}igx) {
 		my $word=$1;
 		if (lc $word eq "and") {
 			$code.=" &&";
@@ -847,85 +1066,199 @@ sub pagespec_translate ($) { #{{{
 		elsif ($word eq "(" || $word eq ")" || $word eq "!") {
 			$code.=" ".$word;
 		}
-		elsif ($word =~ /^(link|backlink|created_before|created_after|creation_month|creation_year|creation_day)\((.+)\)$/) {
-			$code.=" match_$1(\$page, ".safequote($2).")";
+		elsif ($word =~ /^(\w+)\((.*)\)$/) {
+			if (exists $IkiWiki::PageSpec::{"match_$1"}) {
+				$code.="IkiWiki::PageSpec::match_$1(\$page, ".safequote($2).", \@params)";
+			}
+			else {
+				$code.=" 0";
+			}
 		}
 		else {
-			$code.=" match_glob(\$page, ".safequote($word).")";
+			$code.=" IkiWiki::PageSpec::match_glob(\$page, ".safequote($word).", \@params)";
 		}
 	}
 
 	return $code;
 } #}}}
 
-sub pagespec_match ($$) { #{{{
+sub pagespec_match ($$;@) { #{{{
 	my $page=shift;
 	my $spec=shift;
+	my @params=@_;
+
+	# Backwards compatability with old calling convention.
+	if (@params == 1) {
+		unshift @params, "location";
+	}
+
+	my $ret=eval pagespec_translate($spec);
+	return IkiWiki::FailReason->new("syntax error") if $@;
+	return $ret;
+} #}}}
 
-	return eval pagespec_translate($spec);
+package IkiWiki::FailReason;
+
+use overload ( #{{{
+	'""'	=> sub { ${$_[0]} },
+	'0+'	=> sub { 0 },
+	'!'	=> sub { bless $_[0], 'IkiWiki::SuccessReason'},
+	fallback => 1,
+); #}}}
+
+sub new { #{{{
+	bless \$_[1], $_[0];
 } #}}}
 
-sub match_glob ($$) { #{{{
+package IkiWiki::SuccessReason;
+
+use overload ( #{{{
+	'""'	=> sub { ${$_[0]} },
+	'0+'	=> sub { 1 },
+	'!'	=> sub { bless $_[0], 'IkiWiki::FailReason'},
+	fallback => 1,
+); #}}}
+
+sub new { #{{{
+	bless \$_[1], $_[0];
+}; #}}}
+
+package IkiWiki::PageSpec;
+
+sub match_glob ($$;@) { #{{{
 	my $page=shift;
 	my $glob=shift;
+	my %params=@_;
+	
+	my $from=exists $params{location} ? $params{location} : "";
+	
+	# relative matching
+	if ($glob =~ m!^\./!) {
+		$from=~s#/?[^/]+$##;
+		$glob=~s#^\./##;
+		$glob="$from/$glob" if length $from;
+	}
 
 	# turn glob into safe regexp
 	$glob=quotemeta($glob);
 	$glob=~s/\\\*/.*/g;
 	$glob=~s/\\\?/./g;
 
-	return $page=~/^$glob$/i;
+	if ($page=~/^$glob$/i) {
+		return IkiWiki::SuccessReason->new("$glob matches $page");
+	}
+	else {
+		return IkiWiki::FailReason->new("$glob does not match $page");
+	}
 } #}}}
 
-sub match_link ($$) { #{{{
+sub match_link ($$;@) { #{{{
 	my $page=shift;
 	my $link=lc(shift);
+	my %params=@_;
+
+	my $from=exists $params{location} ? $params{location} : "";
+
+	# relative matching
+	if ($link =~ m!^\.! && defined $from) {
+		$from=~s#/?[^/]+$##;
+		$link=~s#^\./##;
+		$link="$from/$link" if length $from;
+	}
 
-	my $links = $links{$page} or return undef;
+	my $links = $IkiWiki::links{$page} or return undef;
+	return IkiWiki::FailReason->new("$page has no links") unless @$links;
+	my $bestlink = IkiWiki::bestlink($from, $link);
 	foreach my $p (@$links) {
-		return 1 if lc $p eq $link;
+		if (length $bestlink) {
+			return IkiWiki::SuccessReason->new("$page links to $link")
+				if $bestlink eq IkiWiki::bestlink($page, $p);
+		}
+		else {
+			return IkiWiki::SuccessReason->new("$page links to page matching $link")
+				if match_glob($p, $link, %params);
+		}
 	}
-	return 0;
+	return IkiWiki::FailReason->new("$page does not link to $link");
 } #}}}
 
-sub match_backlink ($$) { #{{{
-	match_link(pop, pop);
+sub match_backlink ($$;@) { #{{{
+	match_link($_[1], $_[0], @_);
 } #}}}
 
-sub match_created_before ($$) { #{{{
+sub match_created_before ($$;@) { #{{{
 	my $page=shift;
 	my $testpage=shift;
 
-	if (exists $pagectime{$testpage}) {
-		return $pagectime{$page} < $pagectime{$testpage};
+	if (exists $IkiWiki::pagectime{$testpage}) {
+		if ($IkiWiki::pagectime{$page} < $IkiWiki::pagectime{$testpage}) {
+			IkiWiki::SuccessReason->new("$page created before $testpage");
+		}
+		else {
+			IkiWiki::FailReason->new("$page not created before $testpage");
+		}
 	}
 	else {
-		return 0;
+		return IkiWiki::FailReason->new("$testpage has no ctime");
 	}
 } #}}}
 
-sub match_created_after ($$) { #{{{
+sub match_created_after ($$;@) { #{{{
 	my $page=shift;
 	my $testpage=shift;
 
-	if (exists $pagectime{$testpage}) {
-		return $pagectime{$page} > $pagectime{$testpage};
+	if (exists $IkiWiki::pagectime{$testpage}) {
+		if ($IkiWiki::pagectime{$page} > $IkiWiki::pagectime{$testpage}) {
+			IkiWiki::SuccessReason->new("$page created after $testpage");
+		}
+		else {
+			IkiWiki::FailReason->new("$page not created after $testpage");
+		}
 	}
 	else {
-		return 0;
+		return IkiWiki::FailReason->new("$testpage has no ctime");
 	}
 } #}}}
 
-sub match_creation_day ($$) { #{{{
-	return ((gmtime($pagectime{shift()}))[3] == shift);
+sub match_creation_day ($$;@) { #{{{
+	if ((gmtime($IkiWiki::pagectime{shift()}))[3] == shift) {
+		return IkiWiki::SuccessReason->new("creation_day matched");
+	}
+	else {
+		return IkiWiki::FailReason->new("creation_day did not match");
+	}
+} #}}}
+
+sub match_creation_month ($$;@) { #{{{
+	if ((gmtime($IkiWiki::pagectime{shift()}))[4] + 1 == shift) {
+		return IkiWiki::SuccessReason->new("creation_month matched");
+	}
+	else {
+		return IkiWiki::FailReason->new("creation_month did not match");
+	}
 } #}}}
 
-sub match_creation_month ($$) { #{{{
-	return ((gmtime($pagectime{shift()}))[4] + 1 == shift);
+sub match_creation_year ($$;@) { #{{{
+	if ((gmtime($IkiWiki::pagectime{shift()}))[5] + 1900 == shift) {
+		return IkiWiki::SuccessReason->new("creation_year matched");
+	}
+	else {
+		return IkiWiki::FailReason->new("creation_year did not match");
+	}
 } #}}}
 
-sub match_creation_year ($$) { #{{{
-	return ((gmtime($pagectime{shift()}))[5] + 1900 == shift);
+sub match_user ($$;@) { #{{{
+	shift;
+	my $user=shift;
+	my %params=@_;
+
+	return IkiWiki::FailReason->new("cannot match user") unless exists $params{user};
+	if ($user eq $params{user}) {
+		return IkiWiki::SuccessReason->new("user is $user")
+	}
+	else {
+		return IkiWiki::FailReason->new("user is not $user");
+	}
 } #}}}
 
 1