X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/419de149a6b4c1cf598f33f0c96a2a21104528ec..66bc27b485e6dd167d0394db18a078d5b7977ae3:/IkiWiki/Plugin/po.pm?ds=sidebyside

diff --git a/IkiWiki/Plugin/po.pm b/IkiWiki/Plugin/po.pm
index 3b92583a1..daac95eb1 100644
--- a/IkiWiki/Plugin/po.pm
+++ b/IkiWiki/Plugin/po.pm
@@ -1,15 +1,25 @@
 #!/usr/bin/perl
 # .po as a wiki page type
 # Licensed under GPL v2 or greater
-# Copyright (C) 2008 intrigeri <intrigeri@boum.org>
+# Copyright (C) 2008-2009 intrigeri <intrigeri@boum.org>
 # inspired by the GPL'd po4a-translate,
 # which is Copyright 2002, 2003, 2004 by Martin Quinson (mquinson#debian.org)
 package IkiWiki::Plugin::po;
 
 use warnings;
 use strict;
-use IkiWiki 2.00;
+use IkiWiki 3.00;
 use Encode;
+BEGIN {
+	eval 'use Locale::Po4a::Common qw(nowrapi18n)';
+	if ($@) {
+		warning(sprintf(gettext('%s is too old, can not disable %s; '.
+					'a denial of service can thus be '.
+					'triggered by malicious content'),
+				'Locale::Po4a', 'Text::WrapI18N'));
+		eval 'use Locale::Po4a::Common';
+	}
+}
 use Locale::Po4a::Chooser;
 use Locale::Po4a::Po;
 use File::Basename;
@@ -17,28 +27,34 @@ use File::Copy;
 use File::Spec;
 use File::Temp;
 use Memoize;
+use UNIVERSAL;
 
 my %translations;
-our %filtered;
+my @origneedsbuild;
+my %origsubs;
 
+memoize("istranslatable");
 memoize("_istranslation");
 memoize("percenttranslated");
-# FIXME: memoizing istranslatable() makes some test cases fail once every
-# two tries; this may be related to the artificial way the testsuite is
-# run, or not.
-# memoize("istranslatable");
-
-# backup references to subs that will be overriden
-my %origsubs;
 
-sub import { #{{{
+sub import {
 	hook(type => "getsetup", id => "po", call => \&getsetup);
 	hook(type => "checkconfig", id => "po", call => \&checkconfig);
 	hook(type => "needsbuild", id => "po", call => \&needsbuild);
+	hook(type => "scan", id => "po", call => \&scan, last =>1);
 	hook(type => "filter", id => "po", call => \&filter);
 	hook(type => "htmlize", id => "po", call => \&htmlize);
 	hook(type => "pagetemplate", id => "po", call => \&pagetemplate, last => 1);
+	hook(type => "postscan", id => "po", call => \&postscan);
+	hook(type => "rename", id => "po", call => \&renamepages, first => 1);
+	hook(type => "delete", id => "po", call => \&mydelete);
+	hook(type => "change", id => "po", call => \&change);
+	hook(type => "checkcontent", id => "po", call => \&checkcontent);
+	hook(type => "canremove", id => "po", call => \&canremove);
+	hook(type => "canrename", id => "po", call => \&canrename);
 	hook(type => "editcontent", id => "po", call => \&editcontent);
+	hook(type => "formbuilder_setup", id => "po", call => \&formbuilder_setup, last => 1);
+	hook(type => "formbuilder", id => "po", call => \&formbuilder);
 
 	$origsubs{'bestlink'}=\&IkiWiki::bestlink;
 	inject(name => "IkiWiki::bestlink", call => \&mybestlink);
@@ -46,13 +62,35 @@ sub import { #{{{
 	inject(name => "IkiWiki::beautify_urlpath", call => \&mybeautify_urlpath);
 	$origsubs{'targetpage'}=\&IkiWiki::targetpage;
 	inject(name => "IkiWiki::targetpage", call => \&mytargetpage);
-} #}}}
+	$origsubs{'urlto'}=\&IkiWiki::urlto;
+	inject(name => "IkiWiki::urlto", call => \&myurlto);
+	$origsubs{'nicepagetitle'}=\&IkiWiki::nicepagetitle;
+	inject(name => "IkiWiki::nicepagetitle", call => \&mynicepagetitle);
+	$origsubs{'cgiurl'}=\&IkiWiki::cgiurl;
+	inject(name => "IkiWiki::cgiurl", call => \&mycgiurl);
+}
+
+
+# ,----
+# | Table of contents
+# `----
+
+# 1. Hooks
+# 2. Injected functions
+# 3. Blackboxes for private data
+# 4. Helper functions
+# 5. PageSpec's
 
-sub getsetup () { #{{{
+
+# ,----
+# | Hooks
+# `----
+
+sub getsetup () {
 	return
 		plugin => {
 			safe => 0,
-			rebuild => 1, # format plugin & changes html filenames
+			rebuild => 1,
 		},
 		po_master_language => {
 			type => "string",
@@ -87,479 +125,1015 @@ sub getsetup () { #{{{
 			type => "string",
 			example => "current",
 			description => "internal linking behavior (default/current/negotiated)",
-			safe => 0,
+			safe => 1,
 			rebuild => 1,
 		},
-} #}}}
-
-sub islanguagecode ($) { #{{{
-    my $code=shift;
-    return ($code =~ /^[a-z]{2}$/);
-} #}}}
+		po_translation_status_in_links => {
+			type => "boolean",
+			example => 1,
+			description => "display translation status in links to translations",
+			safe => 1,
+			rebuild => 1,
+		},
+}
 
-sub checkconfig () { #{{{
+sub checkconfig () {
 	foreach my $field (qw{po_master_language po_slave_languages}) {
 		if (! exists $config{$field} || ! defined $config{$field}) {
-			error(sprintf(gettext("Must specify %s"), $field));
+			error(sprintf(gettext("Must specify %s when using the %s plugin"),
+				      $field, 'po'));
 		}
 	}
+	if (! (keys %{$config{po_slave_languages}})) {
+		error(gettext("At least one slave language must be defined ".
+			      "in po_slave_languages when using the po plugin"));
+	}
 	map {
 		islanguagecode($_)
-		    or error(sprintf(gettext("%s is not a valid language code"), $_));
+			or error(sprintf(gettext("%s is not a valid language code"), $_));
 	} ($config{po_master_language}{code}, keys %{$config{po_slave_languages}});
-	if (! exists $config{po_link_to} ||
-	    ! defined $config{po_link_to}) {
-		$config{po_link_to}="default";
-	}
 	if (! exists $config{po_translatable_pages} ||
 	    ! defined $config{po_translatable_pages}) {
 		$config{po_translatable_pages}="";
 	}
-	if ($config{po_link_to} eq "negotiated" && ! $config{usedirs}) {
-		error(gettext("po_link_to=negotiated requires usedirs to be set"));
+	if (! exists $config{po_link_to} ||
+	    ! defined $config{po_link_to}) {
+		$config{po_link_to}='default';
+	}
+	elsif (! grep {
+			$config{po_link_to} eq $_
+		} ('default', 'current', 'negotiated')) {
+		warn(sprintf(gettext('%s is not a valid value for po_link_to, falling back to po_link_to=default'),
+			     $config{po_link_to}));
+		$config{po_link_to}='default';
+	}
+	elsif ($config{po_link_to} eq "negotiated" && ! $config{usedirs}) {
+		warn(gettext('po_link_to=negotiated requires usedirs to be enabled, falling back to po_link_to=default'));
+		$config{po_link_to}='default';
+	}
+	if (! exists $config{po_translation_status_in_links} ||
+	    ! defined $config{po_translation_status_in_links}) {
+		$config{po_translation_status_in_links}=1;
 	}
 	push @{$config{wiki_file_prune_regexps}}, qr/\.pot$/;
-} #}}}
+}
 
-sub potfile ($) { #{{{
-	my $masterfile=shift;
+sub needsbuild () {
+	my $needsbuild=shift;
 
-	(my $name, my $dir, my $suffix) = fileparse($masterfile, qr/\.[^.]*/);
-	$dir='' if $dir eq './';
-	return File::Spec->catpath('', $dir, $name . ".pot");
-} #}}}
+	# backup @needsbuild content so that change() can know whether
+	# a given master page was rendered because its source file was changed
+	@origneedsbuild=(@$needsbuild);
 
-sub pofile ($$) { #{{{
-	my $masterfile=shift;
-	my $lang=shift;
+	flushmemoizecache();
+	buildtranslationscache();
 
-	(my $name, my $dir, my $suffix) = fileparse($masterfile, qr/\.[^.]*/);
-	$dir='' if $dir eq './';
-	return File::Spec->catpath('', $dir, $name . "." . $lang . ".po");
-} #}}}
+	# make existing translations depend on the corresponding master page
+	foreach my $master (keys %translations) {
+		map add_depends($_, $master), values %{otherlanguages($master)};
+	}
+}
 
-sub refreshpot ($) { #{{{
-	my $masterfile=shift;
+# Massage the recorded state of internal links so that:
+# - it matches the actually generated links, rather than the links as written
+#   in the pages' source
+# - backlinks are consistent in all cases
+sub scan (@) {
+	my %params=@_;
+	my $page=$params{page};
+	my $content=$params{content};
 
-	my $potfile=potfile($masterfile);
-	my %options = ("markdown" => (pagetype($masterfile) eq 'mdwn') ? 1 : 0);
-	my $doc=Locale::Po4a::Chooser::new('text',%options);
-	$doc->read($masterfile);
-	$doc->{TT}{utf_mode} = 1;
-	$doc->{TT}{file_in_charset} = 'utf-8';
-	$doc->{TT}{file_out_charset} = 'utf-8';
-	# let's cheat a bit to force porefs option to be passed to Locale::Po4a::Po;
-	# this is undocument use of internal Locale::Po4a::TransTractor's data,
-	# compulsory since this module prevents us from using the porefs option.
-	my %po_options = ('porefs' => 'none');
-	$doc->{TT}{po_out}=Locale::Po4a::Po->new(\%po_options);
-	$doc->{TT}{po_out}->set_charset('utf-8');
-	# do the actual work
-	$doc->parse;
-	$doc->writepo($potfile);
-} #}}}
+	return unless UNIVERSAL::can("IkiWiki::Plugin::link", "import");
 
-sub refreshpofiles ($@) { #{{{
-	my $masterfile=shift;
-	my @pofiles=@_;
+	if (istranslation($page)) {
+		foreach my $destpage (@{$links{$page}}) {
+			if (istranslatable($destpage)) {
+				# replace one occurence of $destpage in $links{$page}
+				# (we only want to replace the one that was added by
+				# IkiWiki::Plugin::link::scan, other occurences may be
+				# there for other reasons)
+				for (my $i=0; $i<@{$links{$page}}; $i++) {
+					if (@{$links{$page}}[$i] eq $destpage) {
+						@{$links{$page}}[$i] = $destpage . '.' . lang($page);
+						last;
+					}
+				}
+			}
+		}
+	}
+	elsif (! istranslatable($page) && ! istranslation($page)) {
+		foreach my $destpage (@{$links{$page}}) {
+			if (istranslatable($destpage)) {
+				# make sure any destpage's translations has
+				# $page in its backlinks
+				push @{$links{$page}},
+					values %{otherlanguages($destpage)};
+			}
+		}
+	}
+}
 
-	my $potfile=potfile($masterfile);
-	error("[po/refreshpofiles] POT file ($potfile) does not exist") unless (-e $potfile);
+# We use filter to convert PO to the master page's format,
+# since the rest of ikiwiki should not work on PO files.
+sub filter (@) {
+	my %params = @_;
 
-	foreach my $pofile (@pofiles) {
-		if (-e $pofile) {
-			system("msgmerge", "-U", "--backup=none", $pofile, $potfile) == 0
-				or error("[po/refreshpofiles:$pofile] failed to update");
-		}
-		else {
-			File::Copy::syscopy($potfile,$pofile)
-				or error("[po/refreshpofiles:$pofile] failed to copy the POT file");
+	my $page = $params{page};
+	my $destpage = $params{destpage};
+	my $content = $params{content};
+	if (istranslation($page) && ! alreadyfiltered($page, $destpage)) {
+		$content = po_to_markup($page, $content);
+		setalreadyfiltered($page, $destpage);
+	}
+	return $content;
+}
+
+sub htmlize (@) {
+	my %params=@_;
+
+	my $page = $params{page};
+	my $content = $params{content};
+
+	# ignore PO files this plugin did not create
+	return $content unless istranslation($page);
+
+	# force content to be htmlize'd as if it was the same type as the master page
+	return IkiWiki::htmlize($page, $page,
+				pagetype(srcfile($pagesources{masterpage($page)})),
+				$content);
+}
+
+sub pagetemplate (@) {
+	my %params=@_;
+	my $page=$params{page};
+	my $destpage=$params{destpage};
+	my $template=$params{template};
+
+	my ($masterpage, $lang) = istranslation($page);
+
+	if (istranslation($page) && $template->query(name => "percenttranslated")) {
+		$template->param(percenttranslated => percenttranslated($page));
+	}
+	if ($template->query(name => "istranslation")) {
+		$template->param(istranslation => scalar istranslation($page));
+	}
+	if ($template->query(name => "istranslatable")) {
+		$template->param(istranslatable => istranslatable($page));
+	}
+	if ($template->query(name => "HOMEPAGEURL")) {
+		$template->param(homepageurl => homepageurl($page));
+	}
+	if ($template->query(name => "otherlanguages")) {
+		$template->param(otherlanguages => [otherlanguagesloop($page)]);
+		map add_depends($page, $_), (values %{otherlanguages($page)});
+	}
+	# Rely on IkiWiki::Render's genpage() to decide wether
+	# a discussion link should appear on $page; this is not
+	# totally accurate, though: some broken links may be generated
+	# when cgiurl is disabled.
+	# This compromise avoids some code duplication, and will probably
+	# prevent future breakage when ikiwiki internals change.
+	# Known limitations are preferred to future random bugs.
+	if ($template->param('discussionlink') && istranslation($page)) {
+		$template->param('discussionlink' => htmllink(
+							$page,
+							$destpage,
+							$masterpage . '/' . gettext("Discussion"),
+							noimageinline => 1,
+							forcesubpage => 0,
+							linktext => gettext("Discussion"),
+							));
+	}
+	# Remove broken parentlink to ./index.html on home page's translations.
+	# It works because this hook has the "last" parameter set, to ensure it
+	# runs after parentlinks' own pagetemplate hook.
+	if ($template->param('parentlinks')
+	    && istranslation($page)
+	    && $masterpage eq "index") {
+		$template->param('parentlinks' => []);
+	}
+} # }}}
+
+sub postscan (@) {
+	my %params = @_;
+	my $page = $params{page};
+
+	# backlinks involve back-dependencies, so that nicepagetitle effects,
+	# such as translation status displayed in links, are updated
+	use IkiWiki::Render;
+	map add_depends($page, $_), keys %{$IkiWiki::backlinks{$page}};
+}
+
+# Add the renamed page translations to the list of to-be-renamed pages.
+sub renamepages($$$) {
+	my ($torename, $cgi, $session) = (shift, shift, shift);
+
+	# copy the initial array, so that we can iterate on it AND
+	# modify it at the same time, without iterating on the items we
+	# pushed on it ourselves
+	my @torename=@{$torename};
+
+	# Save the page(s) the user asked to rename, so that our
+	# canrename hook can tell the difference between:
+	#  - a translation being renamed as a consequence of its master page
+	#    being renamed
+	#  - a user trying to directly rename a translation
+	# This is why this hook has to be run first, before @torename is modified
+	# by other plugins.
+	$session->param(po_orig_torename => [ @torename ]);
+	IkiWiki::cgi_savesession($session);
+
+	foreach my $rename (@torename) {
+		next unless istranslatable($rename->{src});
+		my %otherpages=%{otherlanguages($rename->{src})};
+		while (my ($lang, $otherpage) = each %otherpages) {
+			push @{$torename}, {
+				src => $otherpage,
+				srcfile => $pagesources{$otherpage},
+				dest => otherlanguage($rename->{dest}, $lang),
+				destfile => $rename->{dest}.".".$lang.".po",
+				required => 0,
+			};
 		}
 	}
-} #}}}
+}
 
-sub needsbuild () { #{{{
-	my $needsbuild=shift;
+sub mydelete(@) {
+	my @deleted=@_;
+
+	map { deletetranslations($_) } grep istranslatablefile($_), @deleted;
+}
 
-	# build %translations, using istranslation's side-effect
-	foreach my $page (keys %pagesources) {
-		istranslation($page);
+sub change(@) {
+	my @rendered=@_;
+
+	# All meta titles are first extracted at scan time, i.e. before we turn
+	# PO files back into translated markdown; escaping of double-quotes in
+	# PO files breaks the meta plugin's parsing enough to save ugly titles
+	# to %pagestate at this time.
+	#
+	# Then, at render time, every page's passes on row through the Great
+	# Rendering Chain (filter->preprocess->linkify->htmlize), and the meta
+	# plugin's preprocess hook is this time in a position to correctly
+	# extract the titles from slave pages.
+	#
+	# This is, unfortunately, too late: if the page A, linking to the page B,
+	# is rendered before B, it will display the wrongly-extracted meta title
+	# as the link text to B.
+	#
+	# On the one hand, such a corner case only happens on rebuild: on
+	# refresh, every rendered page is fixed to contain correct meta titles.
+	# On the other hand, it can take some time to get every page fixed.
+	# We therefore re-render every rendered page after a rebuild to fix them
+	# at once. As this more or less doubles the time needed to rebuild the
+	# wiki, we do so only when really needed.
+
+	if (scalar @rendered
+	    && exists $config{rebuild} && defined $config{rebuild} && $config{rebuild}
+	    && UNIVERSAL::can("IkiWiki::Plugin::meta", "getsetup")
+	    && exists $config{meta_overrides_page_title}
+	    && defined $config{meta_overrides_page_title}
+	    && $config{meta_overrides_page_title}) {
+		debug(sprintf(gettext("re-rendering all pages to fix meta titles")));
+		resetalreadyfiltered();
+		require IkiWiki::Render;
+		foreach my $file (@rendered) {
+			debug(sprintf(gettext("rendering %s"), $file));
+			IkiWiki::render($file);
+		}
 	}
 
-	# refresh/create POT and PO files as needed
 	my $updated_po_files=0;
-	foreach my $page (keys %pagesources) {
-		if (istranslatable($page)) {
-			my $pageneedsbuild = grep { $_ eq $pagesources{$page} } @$needsbuild;
-			my $updated_pot_file=0;
-			my $file=srcfile($pagesources{$page});
-			if ($pageneedsbuild || ! -e potfile($file)) {
-				refreshpot($file);
-				$updated_pot_file=1;
-			}
-			my @pofiles;
-			foreach my $lang (keys %{$config{po_slave_languages}}) {
-				my $pofile=pofile($file, $lang);
-				my $pofile_rel=pofile($pagesources{$page}, $lang);
-				if ($pageneedsbuild || $updated_pot_file || ! -e $pofile) {
-					push @pofiles, $pofile;
-					push @$needsbuild, $pofile_rel
-					  unless grep { $_ eq $pofile_rel } @$needsbuild;
-				}
-			}
-			if (@pofiles) {
-				refreshpofiles($file, @pofiles) ;
-				map { IkiWiki::rcs_add($_); } @pofiles if ($config{rcs});
-				$updated_po_files = 1;
-			}
+
+	# Refresh/create POT and PO files as needed.
+	foreach my $file (grep {istranslatablefile($_)} @rendered) {
+		my $page=pagename($file);
+		my $masterfile=srcfile($file);
+		my $updated_pot_file=0;
+		# Only refresh Pot file if it does not exist, or if
+		# $pagesources{$page} was changed: don't if only the HTML was
+		# refreshed, e.g. because of a dependency.
+		if ((grep { $_ eq $pagesources{$page} } @origneedsbuild)
+		    || ! -e potfile($masterfile)) {
+			refreshpot($masterfile);
+			$updated_pot_file=1;
+		}
+		my @pofiles;
+		map {
+			push @pofiles, $_ if ($updated_pot_file || ! -e $_);
+		} (pofiles($masterfile));
+		if (@pofiles) {
+			refreshpofiles($masterfile, @pofiles);
+			map { IkiWiki::rcs_add($_) } @pofiles if $config{rcs};
+			$updated_po_files=1;
 		}
 	}
 
-	# check staged changes in
 	if ($updated_po_files) {
-		if ($config{rcs}) {
-			IkiWiki::disable_commit_hook();
-			IkiWiki::rcs_commit_staged(gettext("updated PO files"),
-				"refreshpofiles", "127.0.0.1");
-			IkiWiki::enable_commit_hook();
-			IkiWiki::rcs_update();
-		}
-		# refresh module's private variables
-		undef %filtered;
-		undef %translations;
-		foreach my $page (keys %pagesources) {
-			istranslation($page);
-		}
+		commit_and_refresh(
+			gettext("updated PO files"),
+			"IkiWiki::Plugin::po::change");
 	}
+}
 
-	# make existing translations depend on the corresponding master page
-	foreach my $master (keys %translations) {
-		foreach my $slave (values %{$translations{$master}}) {
-			add_depends($slave, $master);
+sub checkcontent (@) {
+	my %params=@_;
+
+	if (istranslation($params{page})) {
+		my $res = isvalidpo($params{content});
+		if ($res) {
+			return undef;
+		}
+		else {
+			return "$res";
 		}
 	}
-} #}}}
+	return undef;
+}
 
-sub mytargetpage ($$) { #{{{
-	my $page=shift;
-	my $ext=shift;
+sub canremove ($$$) {
+	my ($page, $cgi, $session) = (shift, shift, shift);
 
 	if (istranslation($page)) {
-		my ($masterpage, $lang) = ($page =~ /(.*)[.]([a-z]{2})$/);
-		if (! $config{usedirs} || $masterpage eq 'index') {
-			return $masterpage . "." . $lang . "." . $ext;
-		}
-		else {
-			return $masterpage . "/index." . $lang . "." . $ext;
+		return gettext("Can not remove a translation. Removing the master page, ".
+			       "though, removes its translations as well.");
+	}
+	return undef;
+}
+
+sub canrename ($$@) {
+	my ($cgi, $session) = (shift, shift);
+	my %params = @_;
+
+	if (istranslation($params{src})) {
+		my $masterpage = masterpage($params{src});
+		# Tell the difference between:
+		#  - a translation being renamed as a consequence of its master page
+		#    being renamed, which is allowed
+		#  - a user trying to directly rename a translation, which is forbidden
+		# by looking for the master page in the list of to-be-renamed pages we
+		# saved early in the renaming process.
+		my $orig_torename = $session->param("po_orig_torename");
+		unless (scalar grep { $_->{src} eq $masterpage } @{$orig_torename}) {
+			return gettext("Can not rename a translation. Renaming the master page, ".
+				       "though, renames its translations as well.");
 		}
 	}
-	elsif (istranslatable($page)) {
-		if (! $config{usedirs} || $page eq 'index') {
-			return $page . "." . $config{po_master_language}{code} . "." . $ext;
+	return undef;
+}
+
+# As we're previewing or saving a page, the content may have
+# changed, so tell the next filter() invocation it must not be lazy.
+sub editcontent () {
+	my %params=@_;
+
+	unsetalreadyfiltered($params{page}, $params{page});
+	return $params{content};
+}
+
+sub formbuilder_setup (@) {
+	my %params=@_;
+	my $form=$params{form};
+	my $q=$params{cgi};
+
+	return unless defined $form->field("do");
+
+	if ($form->field("do") eq "create") {
+		# Warn the user: new pages must be written in master language.
+		my $template=template("pocreatepage.tmpl");
+		$template->param(LANG => $config{po_master_language}{name});
+		$form->tmpl_param(message => $template->output);
+	}
+	elsif ($form->field("do") eq "edit") {
+		# Remove the rename/remove buttons on slave pages.
+		# This has to be done after the rename/remove plugins have added
+		# their buttons, which is why this hook must be run last.
+		# The canrename/canremove hooks already ensure this is forbidden
+		# at the backend level, so this is only UI sugar.
+		if (istranslation($form->field("page"))) {
+			map {
+				for (my $i = 0; $i < @{$params{buttons}}; $i++) {
+					if (@{$params{buttons}}[$i] eq $_) {
+						delete  @{$params{buttons}}[$i];
+						last;
+					}
+				}
+			} qw(Rename Remove);
 		}
-		else {
-			return $page . "/index." . $config{po_master_language}{code} . "." . $ext;
+	}
+}
+
+sub formbuilder (@) {
+	my %params=@_;
+	my $form=$params{form};
+	my $q=$params{cgi};
+
+	return unless defined $form->field("do");
+
+	# Do not allow to create pages of type po: they are automatically created.
+	# The main reason to do so is to bypass the "favor the type of linking page
+	# on page creation" logic, which is unsuitable when a broken link is clicked
+	# on a slave (PO) page.
+	# This cannot be done in the formbuilder_setup hook as the list of types is
+	# computed later.
+	if ($form->field("do") eq "create") {
+	        for my $field ($form->field) {
+			next unless "$field" eq "type";
+			if ($field->type eq 'select') {
+				# remove po from the list of types
+				my @types = grep { $_ ne 'po' } $field->options;
+				$field->options(\@types) if scalar @types;
+			}
+			else {
+				# make sure the default value is not po;
+				# does this case actually happen?
+				debug "po(formbuilder) ".gettext("type field is not select - not implemented yet");
+			}
 		}
 	}
-	return $origsubs{'targetpage'}->($page, $ext);
-} #}}}
+}
+
+# ,----
+# | Injected functions
+# `----
+
+# Implement po_link_to 'current' and 'negotiated' settings.
+sub mybestlink ($$) {
+	my $page=shift;
+	my $link=shift;
+
+	my $res=$origsubs{'bestlink'}->(masterpage($page), $link);
+	if (length $res
+	    && ($config{po_link_to} eq "current" || $config{po_link_to} eq "negotiated")
+	    && istranslatable($res)
+	    && istranslation($page)) {
+		return $res . "." . lang($page);
+	}
+	return $res;
+}
 
-sub mybeautify_urlpath ($) { #{{{
+sub mybeautify_urlpath ($) {
 	my $url=shift;
 
 	my $res=$origsubs{'beautify_urlpath'}->($url);
 	if ($config{po_link_to} eq "negotiated") {
 		$res =~ s!/\Qindex.$config{po_master_language}{code}.$config{htmlext}\E$!/!;
+		$res =~ s!/\Qindex.$config{htmlext}\E$!/!;
+		map {
+			$res =~ s!/\Qindex.$_.$config{htmlext}\E$!/!;
+		} (keys %{$config{po_slave_languages}});
 	}
 	return $res;
-} #}}}
+}
+
+sub mytargetpage ($$) {
+	my $page=shift;
+	my $ext=shift;
+
+	if (istranslation($page) || istranslatable($page)) {
+		my ($masterpage, $lang) = (masterpage($page), lang($page));
+		if (! $config{usedirs} || $masterpage eq 'index') {
+			return $masterpage . "." . $lang . "." . $ext;
+		}
+		else {
+			return $masterpage . "/index." . $lang . "." . $ext;
+		}
+	}
+	return $origsubs{'targetpage'}->($page, $ext);
+}
 
-sub urlto_with_orig_beautiful_urlpath($$) { #{{{
+sub myurlto ($$;$) {
 	my $to=shift;
 	my $from=shift;
+	my $absolute=shift;
 
-	inject(name => "IkiWiki::beautify_urlpath", call => $origsubs{'beautify_urlpath'});
-	my $res=urlto($to, $from);
-	inject(name => "IkiWiki::beautify_urlpath", call => \&mybeautify_urlpath);
+	# workaround hard-coded /index.$config{htmlext} in IkiWiki::urlto()
+	if (! length $to
+	    && $config{po_link_to} eq "current"
+	    && istranslatable('index')) {
+		return IkiWiki::beautify_urlpath(IkiWiki::baseurl($from) . "index." . lang($from) . ".$config{htmlext}");
+	}
+	# avoid using our injected beautify_urlpath if run by cgi_editpage,
+	# so that one is redirected to the just-edited page rather than to the
+	# negociated translation; to prevent unnecessary fiddling with caller/inject,
+	# we only do so when our beautify_urlpath would actually do what we want to
+	# avoid, i.e. when po_link_to = negotiated
+	if ($config{po_link_to} eq "negotiated") {
+		my @caller = caller(1);
+		my $run_by_editpage = 0;
+		$run_by_editpage = 1 if (exists $caller[3] && defined $caller[3]
+					 && $caller[3] eq "IkiWiki::cgi_editpage");
+		inject(name => "IkiWiki::beautify_urlpath", call => $origsubs{'beautify_urlpath'})
+			if $run_by_editpage;
+		my $res = $origsubs{'urlto'}->($to,$from,$absolute);
+		inject(name => "IkiWiki::beautify_urlpath", call => \&mybeautify_urlpath)
+			if $run_by_editpage;
+		return $res;
+	}
+	else {
+		return $origsubs{'urlto'}->($to,$from,$absolute)
+	}
+}
 
-	return $res;
-} #}}}
+sub mynicepagetitle ($;$) {
+	my ($page, $unescaped) = (shift, shift);
 
-sub mybestlink ($$) { #{{{
-	my $page=shift;
-	my $link=shift;
+	my $res = $origsubs{'nicepagetitle'}->($page, $unescaped);
+	return $res unless istranslation($page);
+	return $res unless $config{po_translation_status_in_links};
+	my @caller = caller(1);
+	return $res if (exists $caller[3] && defined $caller[3]
+			&& $caller[3] eq "IkiWiki::Plugin::parentlinks::parentlinks");
+	return $res.' ('.percenttranslated($page).'&nbsp;%)';
+}
 
-	my $res=$origsubs{'bestlink'}->($page, $link);
-	if (length $res) {
-		if ($config{po_link_to} eq "current"
-		    && istranslatable($res)
-		    && istranslation($page)) {
-			my ($masterpage, $curlang) = ($page =~ /(.*)[.]([a-z]{2})$/);
-			return $res . "." . $curlang;
-		}
-		else {
-			return $res;
-		}
+sub mycgiurl (@) {
+	my %params=@_;
+
+	# slave pages have no subpages
+	if (istranslation($params{'from'})) {
+		$params{'from'} = masterpage($params{'from'});
 	}
-	return "";
-} #}}}
+	return $origsubs{'cgiurl'}->(%params);
+}
 
-# We use filter to convert PO to the master page's format,
-# since the rest of ikiwiki should not work on PO files.
-sub filter (@) { #{{{
-	my %params = @_;
+# ,----
+# | Blackboxes for private data
+# `----
 
-	my $page = $params{page};
-	my $destpage = $params{destpage};
-	my $content = decode_utf8(encode_utf8($params{content}));
+{
+	my %filtered;
 
-	return $content if ( ! istranslation($page)
-			     || ( exists $filtered{$page}{$destpage}
-				  && $filtered{$page}{$destpage} eq 1 ));
+	sub alreadyfiltered($$) {
+		my $page=shift;
+		my $destpage=shift;
 
-	# CRLF line terminators make poor Locale::Po4a feel bad
-	$content=~s/\r\n/\n/g;
+		return ( exists $filtered{$page}{$destpage}
+			 && $filtered{$page}{$destpage} eq 1 );
+	}
 
-	# Implementation notes
-	#
-	# 1. Locale::Po4a reads/writes from/to files, and I'm too lazy
-	#    to learn how to disguise a variable as a file.
-	# 2. There are incompatibilities between some File::Temp versions
-	#    (including 0.18, bundled with Lenny's perl-modules package)
-	#    and others (e.g. 0.20, previously present in the archive as
-	#    a standalone package): under certain circumstances, some
-	#    return a relative filename, whereas others return an absolute one;
-	#    we here use this module in a way that is at least compatible
-	#    with 0.18 and 0.20. Beware, hit'n'run refactorers!
-	my $infile = new File::Temp(TEMPLATE => "ikiwiki-po-filter-in.XXXXXXXXXX",
-				    DIR => File::Spec->tmpdir,
-				    UNLINK => 1)->filename;
-	my $outfile = new File::Temp(TEMPLATE => "ikiwiki-po-filter-out.XXXXXXXXXX",
-				     DIR => File::Spec->tmpdir,
-				     UNLINK => 1)->filename;
+	sub setalreadyfiltered($$) {
+		my $page=shift;
+		my $destpage=shift;
+
+		$filtered{$page}{$destpage}=1;
+	}
 
-	writefile(basename($infile), File::Spec->tmpdir, $content);
+	sub unsetalreadyfiltered($$) {
+		my $page=shift;
+		my $destpage=shift;
+
+		if (exists $filtered{$page}{$destpage}) {
+			delete $filtered{$page}{$destpage};
+		}
+	}
+
+	sub resetalreadyfiltered() {
+		undef %filtered;
+	}
+}
+
+# ,----
+# | Helper functions
+# `----
+
+sub maybe_add_leading_slash ($;$) {
+	my $str=shift;
+	my $add=shift;
+	$add=1 unless defined $add;
+	return '/' . $str if $add;
+	return $str;
+}
+
+sub istranslatablefile ($) {
+	my $file=shift;
+
+	return 0 unless defined $file;
+	return 0 if (defined pagetype($file) && pagetype($file) eq 'po');
+	return 0 if $file =~ /\.pot$/;
+	return 0 unless -e "$config{srcdir}/$file"; # underlay dirs may be read-only
+	return 1 if pagespec_match(pagename($file), $config{po_translatable_pages});
+	return;
+}
+
+sub istranslatable ($) {
+	my $page=shift;
+
+	$page=~s#^/##;
+	return 1 if istranslatablefile($pagesources{$page});
+	return;
+}
+
+sub _istranslation ($) {
+	my $page=shift;
+
+	$page='' unless (defined $page && length $page);
+	my $hasleadingslash = ($page=~s#^/##);
+	my $file=$pagesources{$page};
+	return 0 unless (defined $file
+			 && defined pagetype($file)
+			 && pagetype($file) eq 'po');
+	return 0 if $file =~ /\.pot$/;
 
 	my ($masterpage, $lang) = ($page =~ /(.*)[.]([a-z]{2})$/);
-	my $masterfile = srcfile($pagesources{$masterpage});
-	my (@pos,@masters);
-	push @pos,$infile;
-	push @masters,$masterfile;
-	my %options = (
-		"markdown" => (pagetype($masterfile) eq 'mdwn') ? 1 : 0,
-	);
+	return 0 unless (defined $masterpage && defined $lang
+			 && length $masterpage && length $lang
+			 && defined $pagesources{$masterpage}
+			 && defined $config{po_slave_languages}{$lang});
+
+	return (maybe_add_leading_slash($masterpage, $hasleadingslash), $lang)
+		if istranslatable($masterpage);
+}
+
+sub istranslation ($) {
+	my $page=shift;
+
+	if (1 < (my ($masterpage, $lang) = _istranslation($page))) {
+		my $hasleadingslash = ($masterpage=~s#^/##);
+		$translations{$masterpage}{$lang}=$page unless exists $translations{$masterpage}{$lang};
+		return (maybe_add_leading_slash($masterpage, $hasleadingslash), $lang);
+	}
+	return;
+}
+
+sub masterpage ($) {
+	my $page=shift;
+
+	if ( 1 < (my ($masterpage, $lang) = _istranslation($page))) {
+		return $masterpage;
+	}
+	return $page;
+}
+
+sub lang ($) {
+	my $page=shift;
+
+	if (1 < (my ($masterpage, $lang) = _istranslation($page))) {
+		return $lang;
+	}
+	return $config{po_master_language}{code};
+}
+
+sub islanguagecode ($) {
+	my $code=shift;
+
+	return ($code =~ /^[a-z]{2}$/);
+}
+
+sub otherlanguage ($$) {
+	my $page=shift;
+	my $code=shift;
+
+	return masterpage($page) if $code eq $config{po_master_language}{code};
+	return masterpage($page) . '.' . $code;
+}
+
+sub otherlanguages ($) {
+	my $page=shift;
+
+	my %ret;
+	return \%ret unless (istranslation($page) || istranslatable($page));
+	my $curlang=lang($page);
+	foreach my $lang
+		($config{po_master_language}{code}, keys %{$config{po_slave_languages}}) {
+		next if $lang eq $curlang;
+		$ret{$lang}=otherlanguage($page, $lang);
+	}
+	return \%ret;
+}
+
+sub potfile ($) {
+	my $masterfile=shift;
+
+	(my $name, my $dir, my $suffix) = fileparse($masterfile, qr/\.[^.]*/);
+	$dir='' if $dir eq './';
+	return File::Spec->catpath('', $dir, $name . ".pot");
+}
+
+sub pofile ($$) {
+	my $masterfile=shift;
+	my $lang=shift;
+
+	(my $name, my $dir, my $suffix) = fileparse($masterfile, qr/\.[^.]*/);
+	$dir='' if $dir eq './';
+	return File::Spec->catpath('', $dir, $name . "." . $lang . ".po");
+}
+
+sub pofiles ($) {
+	my $masterfile=shift;
+
+	return map pofile($masterfile, $_), (keys %{$config{po_slave_languages}});
+}
+
+sub refreshpot ($) {
+	my $masterfile=shift;
+
+	my $potfile=potfile($masterfile);
+	my %options = ("markdown" => (pagetype($masterfile) eq 'mdwn') ? 1 : 0);
 	my $doc=Locale::Po4a::Chooser::new('text',%options);
-	$doc->process(
-		'po_in_name'	=> \@pos,
-		'file_in_name'	=> \@masters,
-		'file_in_charset'  => 'utf-8',
-		'file_out_charset' => 'utf-8',
-	) or error("[po/filter:$infile]: failed to translate");
-	$doc->write($outfile) or error("[po/filter:$infile] could not write $outfile");
-	$content = readfile($outfile) or error("[po/filter:$infile] could not read $outfile");
+	$doc->{TT}{utf_mode} = 1;
+	$doc->{TT}{file_in_charset} = 'utf-8';
+	$doc->{TT}{file_out_charset} = 'utf-8';
+	$doc->read($masterfile);
+	# let's cheat a bit to force porefs option to be passed to Locale::Po4a::Po;
+	# this is undocument use of internal Locale::Po4a::TransTractor's data,
+	# compulsory since this module prevents us from using the porefs option.
+	$doc->{TT}{po_out}=Locale::Po4a::Po->new({ 'porefs' => 'none' });
+	$doc->{TT}{po_out}->set_charset('utf-8');
+	# do the actual work
+	$doc->parse;
+	IkiWiki::prep_writefile(basename($potfile),dirname($potfile));
+	$doc->writepo($potfile);
+}
 
-	# Unlinking should happen automatically, thanks to File::Temp,
-	# but it does not work here, probably because of the way writefile()
-	# and Locale::Po4a::write() work.
-	unlink $infile, $outfile;
+sub refreshpofiles ($@) {
+	my $masterfile=shift;
+	my @pofiles=@_;
 
-	$filtered{$page}{$destpage}=1;
-	return $content;
-} #}}}
+	my $potfile=potfile($masterfile);
+	(-e $potfile)
+		or error("po(refreshpofiles) ".sprintf(gettext("POT file (%s) does not exist"),
+						       $potfile));
 
-sub htmlize (@) { #{{{
-	my %params=@_;
+	foreach my $pofile (@pofiles) {
+		IkiWiki::prep_writefile(basename($pofile),dirname($pofile));
+		if (-e $pofile) {
+			system("msgmerge", "-U", "--backup=none", $pofile, $potfile) == 0
+				or error("po(refreshpofiles) ".
+					 sprintf(gettext("failed to update %s"),
+						 $pofile));
+		}
+		else {
+			File::Copy::syscopy($potfile,$pofile)
+				or error("po(refreshpofiles) ".
+					 sprintf(gettext("failed to copy the POT file to %s"),
+						 $pofile));
+		}
+	}
+}
 
-	my $page = $params{page};
-	my $content = $params{content};
-	my ($masterpage, $lang) = ($page =~ /(.*)[.]([a-z]{2})$/);
-	my $masterfile = srcfile($pagesources{$masterpage});
+sub buildtranslationscache() {
+	# use istranslation's side-effect
+	map istranslation($_), (keys %pagesources);
+}
 
-	# force content to be htmlize'd as if it was the same type as the master page
-	return IkiWiki::htmlize($page, $page, pagetype($masterfile), $content);
-} #}}}
+sub resettranslationscache() {
+	undef %translations;
+}
+
+sub flushmemoizecache() {
+	Memoize::flush_cache("istranslatable");
+	Memoize::flush_cache("_istranslation");
+	Memoize::flush_cache("percenttranslated");
+}
+
+sub urlto_with_orig_beautiful_urlpath($$) {
+	my $to=shift;
+	my $from=shift;
+
+	inject(name => "IkiWiki::beautify_urlpath", call => $origsubs{'beautify_urlpath'});
+	my $res=urlto($to, $from);
+	inject(name => "IkiWiki::beautify_urlpath", call => \&mybeautify_urlpath);
+
+	return $res;
+}
 
-sub percenttranslated ($) { #{{{
+sub percenttranslated ($) {
 	my $page=shift;
 
-	return gettext("N/A") unless (istranslation($page));
-	my ($masterpage, $lang) = ($page =~ /(.*)[.]([a-z]{2})$/);
+	$page=~s/^\///;
+	return gettext("N/A") unless istranslation($page);
 	my $file=srcfile($pagesources{$page});
-	my $masterfile = srcfile($pagesources{$masterpage});
-	my (@pos,@masters);
-	push @pos,$file;
-	push @masters,$masterfile;
+	my $masterfile = srcfile($pagesources{masterpage($page)});
 	my %options = (
 		"markdown" => (pagetype($masterfile) eq 'mdwn') ? 1 : 0,
 	);
 	my $doc=Locale::Po4a::Chooser::new('text',%options);
 	$doc->process(
-		'po_in_name'	=> \@pos,
-		'file_in_name'	=> \@masters,
+		'po_in_name'	=> [ $file ],
+		'file_in_name'	=> [ $masterfile ],
 		'file_in_charset'  => 'utf-8',
 		'file_out_charset' => 'utf-8',
-	) or error("[po/percenttranslated:$file]: failed to translate");
+	) or error("po(percenttranslated) ".
+		   sprintf(gettext("failed to translate %s"), $page));
 	my ($percent,$hit,$queries) = $doc->stats();
+	$percent =~ s/\.[0-9]+$//;
 	return $percent;
-} #}}}
+}
 
-sub otherlanguages ($) { #{{{
+sub languagename ($) {
+	my $code=shift;
+
+	return $config{po_master_language}{name}
+		if $code eq $config{po_master_language}{code};
+	return $config{po_slave_languages}{$code}
+		if defined $config{po_slave_languages}{$code};
+	return;
+}
+
+sub otherlanguagesloop ($) {
 	my $page=shift;
 
 	my @ret;
-	if (istranslatable($page)) {
-		foreach my $lang (sort keys %{$translations{$page}}) {
-			my $translation = $translations{$page}{$lang};
+	my %otherpages=%{otherlanguages($page)};
+	while (my ($lang, $otherpage) = each %otherpages) {
+		if (istranslation($page) && masterpage($page) eq $otherpage) {
 			push @ret, {
-				url => urlto($translation, $page),
+				url => urlto_with_orig_beautiful_urlpath($otherpage, $page),
 				code => $lang,
-				language => $config{po_slave_languages}{$lang},
-				percent => percenttranslated($translation),
+				language => languagename($lang),
+				master => 1,
 			};
 		}
-	}
-	elsif (istranslation($page)) {
-		my ($masterpage, $curlang) = ($page =~ /(.*)[.]([a-z]{2})$/);
-		push @ret, {
-			url => urlto_with_orig_beautiful_urlpath($masterpage, $page),
-			code => $config{po_master_language}{code},
-			language => $config{po_master_language}{name},
-			master => 1,
-		};
-		foreach my $lang (sort keys %{$translations{$masterpage}}) {
+		else {
 			push @ret, {
-				url => urlto($translations{$masterpage}{$lang}, $page),
+				url => urlto_with_orig_beautiful_urlpath($otherpage, $page),
 				code => $lang,
-				language => $config{po_slave_languages}{$lang},
-				percent => percenttranslated($translations{$masterpage}{$lang}),
-			} unless ($lang eq $curlang);
+				language => languagename($lang),
+				percent => percenttranslated($otherpage),
+			}
 		}
 	}
-	return @ret;
-} #}}}
+	return sort {
+			return -1 if $a->{code} eq $config{po_master_language}{code};
+			return 1 if $b->{code} eq $config{po_master_language}{code};
+			return $a->{language} cmp $b->{language};
+		} @ret;
+}
+
+sub homepageurl (;$) {
+	my $page=shift;
 
-sub pagetemplate (@) { #{{{
-	my %params=@_;
-	my $page=$params{page};
-	my $destpage=$params{destpage};
-	my $template=$params{template};
+	return urlto('', $page);
+}
 
-	my ($masterpage, $lang) = ($page =~ /(.*)[.]([a-z]{2})$/) if istranslation($page);
+sub deletetranslations ($) {
+	my $deletedmasterfile=shift;
 
-	if (istranslation($page) && $template->query(name => "percenttranslated")) {
-		$template->param(percenttranslated => percenttranslated($page));
-	}
-	if ($template->query(name => "istranslation")) {
-		$template->param(istranslation => istranslation($page));
-	}
-	if ($template->query(name => "istranslatable")) {
-		$template->param(istranslatable => istranslatable($page));
-	}
-	if ($template->query(name => "otherlanguages")) {
-		$template->param(otherlanguages => [otherlanguages($page)]);
-		if (istranslatable($page)) {
-			foreach my $translation (values %{$translations{$page}}) {
-				add_depends($page, $translation);
-			}
+	my $deletedmasterpage=pagename($deletedmasterfile);
+	my @todelete;
+	map {
+		my $file = newpagefile($deletedmasterpage.'.'.$_, 'po');
+		my $absfile = "$config{srcdir}/$file";
+		if (-e $absfile && ! -l $absfile && ! -d $absfile) {
+			push @todelete, $file;
 		}
-		elsif (istranslation($page)) {
-			add_depends($page, $masterpage);
-			foreach my $translation (values %{$translations{$masterpage}}) {
-				add_depends($page, $translation);
-			}
+	} keys %{$config{po_slave_languages}};
+
+	map {
+		if ($config{rcs}) {
+			IkiWiki::rcs_remove($_);
 		}
+		else {
+			IkiWiki::prune("$config{srcdir}/$_");
+		}
+	} @todelete;
+
+	if (scalar @todelete) {
+		commit_and_refresh(
+			gettext("removed obsolete PO files"),
+			"IkiWiki::Plugin::po::deletetranslations");
 	}
-	# Rely on IkiWiki::Render's genpage() to decide wether
-	# a discussion link should appear on $page; this is not
-	# totally accurate, though: some broken links may be generated
-	# when cgiurl is disabled.
-	# This compromise avoids some code duplication, and will probably
-	# prevent future breakage when ikiwiki internals change.
-	# Known limitations are preferred to future random bugs.
-	if ($template->param('discussionlink') && istranslation($page)) {
-		$template->param('discussionlink' => htmllink(
-							$page,
-							$destpage,
-							$masterpage . '/' . gettext("Discussion"),
-							noimageinline => 1,
-							forcesubpage => 0,
-							linktext => gettext("Discussion"),
-							));
-	}
-	# remove broken parentlink to ./index.html on home page's translations
-	if ($template->param('parentlinks')
-	    && istranslation($page)
-	    && $masterpage eq "index") {
-		$template->param('parentlinks' => []);
-	}
-} # }}}
+}
 
-sub editcontent () { #{{{
-	my %params=@_;
-	# as we're previewing or saving a page, the content may have
-	# changed, so tell the next filter() invocation it must not be lazy
-	if (exists $filtered{$params{page}}{$params{page}}) {
-		delete $filtered{$params{page}}{$params{page}};
+sub commit_and_refresh ($$) {
+	my ($msg, $author) = (shift, shift);
+
+	if ($config{rcs}) {
+		IkiWiki::disable_commit_hook();
+		IkiWiki::rcs_commit_staged($msg, $author, "127.0.0.1");
+		IkiWiki::enable_commit_hook();
+		IkiWiki::rcs_update();
 	}
-	return $params{content};
-} #}}}
+	# Reinitialize module's private variables.
+	resetalreadyfiltered();
+	resettranslationscache();
+	flushmemoizecache();
+	# Trigger a wiki refresh.
+	require IkiWiki::Render;
+	# without preliminary saveindex/loadindex, refresh()
+	# complains about a lot of uninitialized variables
+	IkiWiki::saveindex();
+	IkiWiki::loadindex();
+	IkiWiki::refresh();
+	IkiWiki::saveindex();
+}
+
+# on success, returns the filtered content.
+# on error, if $nonfatal, warn and return undef; else, error out.
+sub po_to_markup ($$;$) {
+	my ($page, $content) = (shift, shift);
+	my $nonfatal = shift;
+
+	$content = '' unless defined $content;
+	$content = decode_utf8(encode_utf8($content));
+	# CRLF line terminators make poor Locale::Po4a feel bad
+	$content=~s/\r\n/\n/g;
 
-sub istranslatable ($) { #{{{
-	my $page=shift;
+	# There are incompatibilities between some File::Temp versions
+	# (including 0.18, bundled with Lenny's perl-modules package)
+	# and others (e.g. 0.20, previously present in the archive as
+	# a standalone package): under certain circumstances, some
+	# return a relative filename, whereas others return an absolute one;
+	# we here use this module in a way that is at least compatible
+	# with 0.18 and 0.20. Beware, hit'n'run refactorers!
+	my $infile = new File::Temp(TEMPLATE => "ikiwiki-po-filter-in.XXXXXXXXXX",
+				    DIR => File::Spec->tmpdir,
+				    UNLINK => 1)->filename;
+	my $outfile = new File::Temp(TEMPLATE => "ikiwiki-po-filter-out.XXXXXXXXXX",
+				     DIR => File::Spec->tmpdir,
+				     UNLINK => 1)->filename;
 
-	my $file=$pagesources{$page};
+	my $fail = sub ($) {
+		my $msg = "po(po_to_markup) - $page : " . shift;
+		if ($nonfatal) {
+			warn $msg;
+			return undef;
+		}
+		error($msg, sub { unlink $infile, $outfile});
+	};
 
-	if (! defined $file
-	    || (defined pagetype($file) && pagetype($file) eq 'po')
-	    || $file =~ /\.pot$/) {
-		return 0;
-	}
-	return pagespec_match($page, $config{po_translatable_pages});
-} #}}}
+	writefile(basename($infile), File::Spec->tmpdir, $content)
+		or return $fail->(sprintf(gettext("failed to write %s"), $infile));
 
-sub _istranslation ($) { #{{{
-	my $page=shift;
+	my $masterfile = srcfile($pagesources{masterpage($page)});
+	my %options = (
+		"markdown" => (pagetype($masterfile) eq 'mdwn') ? 1 : 0,
+	);
+	my $doc=Locale::Po4a::Chooser::new('text',%options);
+	$doc->process(
+		'po_in_name'	=> [ $infile ],
+		'file_in_name'	=> [ $masterfile ],
+		'file_in_charset'  => 'utf-8',
+		'file_out_charset' => 'utf-8',
+	) or return $fail->(gettext("failed to translate"));
+	$doc->write($outfile)
+		or return $fail->(sprintf(gettext("failed to write %s"), $outfile));
 
-	my $file=$pagesources{$page};
-	if (! defined $file) {
-		return IkiWiki::FailReason->new("no file specified");
-	}
+	$content = readfile($outfile)
+		or return $fail->(sprintf(gettext("failed to read %s"), $outfile));
 
-	if (! defined $file
-	    || ! defined pagetype($file)
- 	    || ! pagetype($file) eq 'po'
-	    || $file =~ /\.pot$/) {
-		return 0;
-	}
+	# Unlinking should happen automatically, thanks to File::Temp,
+	# but it does not work here, probably because of the way writefile()
+	# and Locale::Po4a::write() work.
+	unlink $infile, $outfile;
 
-	my ($masterpage, $lang) = ($page =~ /(.*)[.]([a-z]{2})$/);
-	if (! defined $masterpage || ! defined $lang
-	    || ! (length($masterpage) > 0) || ! (length($lang) > 0)
-	    || ! defined $pagesources{$masterpage}
-	    || ! defined $config{po_slave_languages}{$lang}) {
-		return 0;
-	}
+	return $content;
+}
+
+# returns a SuccessReason or FailReason object
+sub isvalidpo ($) {
+	my $content = shift;
+
+	# NB: we don't use po_to_markup here, since Po4a parser does
+	# not mind invalid PO content
+	$content = '' unless defined $content;
+	$content = decode_utf8(encode_utf8($content));
+
+	# There are incompatibilities between some File::Temp versions
+	# (including 0.18, bundled with Lenny's perl-modules package)
+	# and others (e.g. 0.20, previously present in the archive as
+	# a standalone package): under certain circumstances, some
+	# return a relative filename, whereas others return an absolute one;
+	# we here use this module in a way that is at least compatible
+	# with 0.18 and 0.20. Beware, hit'n'run refactorers!
+	my $infile = new File::Temp(TEMPLATE => "ikiwiki-po-isvalidpo.XXXXXXXXXX",
+				    DIR => File::Spec->tmpdir,
+				    UNLINK => 1)->filename;
 
-	return istranslatable($masterpage);
-} #}}}
+	my $fail = sub ($) {
+		my $msg = '[po/isvalidpo] ' . shift;
+		unlink $infile;
+		return IkiWiki::FailReason->new("$msg");
+	};
 
-sub istranslation ($) { #{{{
-	my $page=shift;
+	writefile(basename($infile), File::Spec->tmpdir, $content)
+		or return $fail->(sprintf(gettext("failed to write %s"), $infile));
 
-	if (_istranslation($page)) {
-		my ($masterpage, $lang) = ($page =~ /(.*)[.]([a-z]{2})$/);
-		$translations{$masterpage}{$lang}=$page unless exists $translations{$masterpage}{$lang};
-		return 1;
+	my $res = (system("msgfmt", "--check", $infile, "-o", "/dev/null") == 0);
+
+	# Unlinking should happen automatically, thanks to File::Temp,
+	# but it does not work here, probably because of the way writefile()
+	# and Locale::Po4a::write() work.
+	unlink $infile;
+
+	if ($res) {
+	    return IkiWiki::SuccessReason->new("valid gettext data");
 	}
-	return 0;
-} #}}}
+	return IkiWiki::FailReason->new("invalid gettext data, go back ".
+					"to previous page to go on with edit");
+}
+
+# ,----
+# | PageSpec's
+# `----
 
 package IkiWiki::PageSpec;
 use warnings;
 use strict;
 use IkiWiki 2.00;
 
-sub match_istranslation ($;@) { #{{{
+sub match_istranslation ($;@) {
 	my $page=shift;
 
 	if (IkiWiki::Plugin::po::istranslation($page)) {
@@ -568,9 +1142,9 @@ sub match_istranslation ($;@) { #{{{
 	else {
 		return IkiWiki::FailReason->new("is not a translation page");
 	}
-} #}}}
+}
 
-sub match_istranslatable ($;@) { #{{{
+sub match_istranslatable ($;@) {
 	my $page=shift;
 
 	if (IkiWiki::Plugin::po::istranslatable($page)) {
@@ -579,53 +1153,31 @@ sub match_istranslatable ($;@) { #{{{
 	else {
 		return IkiWiki::FailReason->new("is not set as translatable in po_translatable_pages");
 	}
-} #}}}
+}
 
-sub match_lang ($$;@) { #{{{
+sub match_lang ($$;@) {
 	my $page=shift;
 	my $wanted=shift;
 
 	my $regexp=IkiWiki::glob2re($wanted);
-	my $lang;
-	my $masterpage;
-
-	if (IkiWiki::Plugin::po::istranslation($page)) {
-		($masterpage, $lang) = ($page =~ /(.*)[.]([a-z]{2})$/);
-	}
-	else {
-		$lang = $config{po_master_language}{code};
-	}
-
+	my $lang=IkiWiki::Plugin::po::lang($page);
 	if ($lang!~/^$regexp$/i) {
 		return IkiWiki::FailReason->new("file language is $lang, not $wanted");
 	}
 	else {
 		return IkiWiki::SuccessReason->new("file language is $wanted");
 	}
-} #}}}
+}
 
-sub match_currentlang ($$;@) { #{{{
+sub match_currentlang ($$;@) {
 	my $page=shift;
-
 	shift;
 	my %params=@_;
-	my ($currentmasterpage, $currentlang, $masterpage, $lang);
 
 	return IkiWiki::FailReason->new("no location provided") unless exists $params{location};
 
-	if (IkiWiki::Plugin::po::istranslation($params{location})) {
-		($currentmasterpage, $currentlang) = ($params{location} =~ /(.*)[.]([a-z]{2})$/);
-	}
-	else {
-		$currentlang = $config{po_master_language}{code};
-	}
-
-	if (IkiWiki::Plugin::po::istranslation($page)) {
-		($masterpage, $lang) = ($page =~ /(.*)[.]([a-z]{2})$/);
-	}
-	else {
-		$lang = $config{po_master_language}{code};
-	}
+	my $currentlang=IkiWiki::Plugin::po::lang($params{location});
+	my $lang=IkiWiki::Plugin::po::lang($page);
 
 	if ($lang eq $currentlang) {
 		return IkiWiki::SuccessReason->new("file language is the same as current one, i.e. $currentlang");
@@ -633,6 +1185,6 @@ sub match_currentlang ($$;@) { #{{{
 	else {
 		return IkiWiki::FailReason->new("file language is $lang, whereas current language is $currentlang");
 	}
-} #}}}
+}
 
 1