It depends on the Perl `Locale::Po4a::Po` library (`apt-get install po4a`).
+[[!toc levels=2]]
+
Introduction
============
A language is chosen as the "master" one, and any other supported
language is a "slave" one.
-A page written in the "master" language is a "master" page, and is
-written in any supported format but PO. It does not have to be named
-a special way: migration from/to this plugin does not imply heavy
+A page written in the "master" language is a "master" page. It can be
+of any page type supported by ikiwiki, except `po`. It does not have to be
+named a special way: migration to this plugin does not imply any page
renaming work.
Example: `bla/page.mdwn` is a "master" Markdown page written in
`bla/page/index.en.html`, else as `bla/page.en.html`.
Any translation of a "master" page into a "slave" language is called
-a "slave" page; it is written in the gettext PO format. PO is now
+a "slave" page; it is written in the gettext PO format. `po` is now
a page type supported by ikiwiki.
Example: `bla/page.fr.po` is the PO "message catalog" used to
Configuration
=============
-`po_master_language` is used to set the master language in
+Supported languages
+-------------------
+
+`po_master_language` is used to set the "master" language in
`ikiwiki.setup`, such as:
po_master_language => { 'code' => 'en', 'name' => 'English' }
translatable. It is a [[ikiwiki/PageSpec]], so you have lots of
control over what kind of pages are translatable.
-The `*.LL.po` translations files are anyway not considered as being
-translatable, so you don't need to worry about excluding them manually
-from this [[ikiwiki/PageSpec]].
+The `.po` files are not considered as being translatable, so you don't need to
+worry about excluding them explicitly from this [[ikiwiki/PageSpec]].
Internal links
--------------
-One can use the `po_link_to_` option in `ikiwiki.setup` to choose how
+The `po_link_to` option in `ikiwiki.setup` is used to decide how
internal links should be generated, depending on web server features
and site-specific preferences.
### Default linking behavior
If `po_link_to` is unset, or set to `default`, ikiwiki's default
-linking behavior is preserved: `\[[page]]` links to the master
+linking behavior is preserved: `\[[destpage]]` links to the master
language's page.
+### Link to current language
+
+If `po_link_to` is set to `current`, `\[[destpage]]` links to the
+`destpage`'s version written in the current page's language, if
+available, *i.e.*:
+
+- `foo/destpage/index.LL.html` if `usedirs` is enabled
+- `foo/destpage.LL.html` if `usedirs` is disabled
+
### Link to negotiated language
If `po_link_to` is set to `negotiated`, `\[[page]]` links to the
(In)compatibility notes:
-- `po_link_to => negotiated` provides no useful behavior if `usedirs`
- is disabled; this option combination is neither implemented nor
- allowed
-- `po_link_to => negotiated` provides no useful behavior if the web
- server does not support Content Negotiation
+- if `usedirs` is disabled, it does not make sense to set `po_link_to`
+ to `negotiated`; this option combination is neither implemented
+ nor allowed.
+- if the web server does not support Content Negotiation, setting
+ `po_link_to` to `negotiated` will produce a unusable website.
-### Link to current language
-If `po_link_to` is set to `current` and the destination page is either
-a translatable page or a translation, `\[[page]]` links to the current
-page's language, *i.e.*:
+Server support
+==============
+
+Apache
+------
-- `foo/page/index.LL.html` if `usedirs` is enabled
-- `foo/page.LL.html` if `usedirs` is disabled
+Using Apache `mod_negotiation` makes it really easy to have Apache
+serve any page in the client's preferred language, if available.
+This is the default Debian Apache configuration.
+When `usedirs` is enabled, one has to set `DirectoryIndex index` for
+the wiki context.
+
+Setting `DefaultLanguage LL` (replace `LL` with your default MIME
+language code) for the wiki context can help to ensure
+`bla/page/index.en.html` is served as `Content-Language: LL`.
+
+lighttpd
+--------
+
+lighttpd unfortunately does not support content negotiation.
+
+**FIXME**: does `mod_magnet` provide the functionality needed to
+ emulate this?
+
+
+Usage
+=====
Templates
---------
-The `OTHERLANGUAGES` loop provides ways to display the existing
-translations and/or master page. One typically adds the following code
-to `templates/page.tmpl`:
+When `po_link_to` is not set to `negotiated`, one should replace some
+occurrences of `BASEURL` with `HOMEPAGEURL` to get correct links to
+the wiki homepage.
+
+The `ISTRANSLATION` and `ISTRANSLATABLE` variables can be used to
+display things only on translatable or translation pages.
+
+### Display page's versions in other languages
+
+The `OTHERLANGUAGES` loop provides ways to display other languages'
+versions of the same page, and the translations' status.
+
+One typically adds the following code to `templates/page.tmpl`:
<TMPL_IF NAME="OTHERLANGUAGES">
<div id="otherlanguages">
<ul>
<TMPL_LOOP NAME="OTHERLANGUAGES">
<li>
- <a href="<TMPL_VAR NAME="URL">"
- class="is_master_<TMPL_VAR NAME="MASTER">">
- <TMPL_VAR NAME="LANGUAGE">
- </a>
+ <a href="<TMPL_VAR NAME="URL">"><TMPL_VAR NAME="LANGUAGE"></a>
+ <TMPL_UNLESS NAME="MASTER">
+ (<TMPL_VAR NAME="PERCENT"> %)
+ </TMPL_UNLESS>
</li>
</TMPL_LOOP>
</ul>
</div>
</TMPL_IF>
+The following variables are available inside the loop (for every page in):
-Server support
-==============
+- `URL` - url to the page
+- `CODE` - two-letters language code
+- `LANGUAGE` - language name (as defined in `po_slave_languages`)
+- `MASTER` - is true (1) if, and only if the page is a "master" page
+- `PERCENT` - for "slave" pages, is set to the translation completeness, in percents
-Apache
-------
+### Display the current translation status
-Using `mod_negotiation` makes it really easy to have Apache serve the
-page in the client's preferred language, if available. This is the
-default Debian Apache configuration.
+The `PERCENTTRANSLATED` variable is set to the translation
+completeness, expressed in percent, on "slave" pages.
-When `usedirs` is enabled, one has to set `DirectoryIndex index` for
-the wiki context.
+One can use it this way:
-Setting `DefaultLanguage LL` (replace `LL` with your default MIME
-language) for the wiki context can be needed, to ensure
-`bla/page/index.en.html` is served as `Content-Language: LL`.
-**FIXME**: is it still needed with the new `.en.html` naming convention?
+ <TMPL_IF NAME="ISTRANSLATION">
+ <div id="percenttranslated">
+ <TMPL_VAR NAME="PERCENTTRANSLATED">
+ </div>
+ </TMPL_IF>
-lighttpd
---------
+Additional PageSpec tests
+-------------------------
-lighttpd unfortunately does not support content negotiation.
+This plugin enhances the regular [[ikiwiki/PageSpec]] syntax with some
+additional tests that are documented [[here|ikiwiki/pagespec/po]].
-**FIXME**: does `mod_magnet` provide the functionality needed to
- emulate this?
+Automatic PO file update
+------------------------
+
+Committing changes to a "master" page:
+
+1. updates the POT file and the PO files for the "slave" languages;
+ the updated PO files are then put under version control;
+2. triggers a refresh of the corresponding HTML slave pages.
+Also, when the plugin has just been enabled, or when a page has just
+been declared as being translatable, the needed POT and PO files are
+created, and the PO files are checked into version control.
+
+Discussion pages and other sub-pages
+------------------------------------
+
+Discussion should happen in the language in which the pages are
+written for real, *i.e.* the "master" one. If discussion pages are
+enabled, "slave" pages therefore link to the "master" page's
+discussion page.
+
+Likewise, "slave" pages are not supposed to have sub-pages;
+[[WikiLinks|wikilink]] that appear on a "slave" page therefore link to
+the master page's sub-pages.
+
+Translating
+-----------
+
+One can edit the PO files using ikiwiki's CGI (a message-by-message
+interface could also be implemented at some point).
+
+If [[tips/untrusted_git_push]] is setup, one can edit the PO files in one's
+preferred `$EDITOR`, without needing to be online.
TODO
====
-Link relationships
-------------------
+Security checks
+---------------
-Should pages using the `OTHERLANGUAGES` template loop be declared as
-linking to the same page in other versions?
+### Security history
-View translation status
------------------------
+The only past security issues I could find in GNU gettext and po4a
+are:
-One should be able to view some information about the translation
-completeness, either for a given page or for the whole wiki.
+- [CVE-2004-0966](http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2004-0966),
+ *i.e.* [Debian bug #278283](http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=278283):
+ the autopoint and gettextize scripts in the GNU gettext package
+ 1.14 and later versions, as used in Trustix Secure Linux 1.5
+ through 2.1 and other operating systems, allows local users to
+ overwrite files via a symlink attack on temporary files.
+- [CVE-2007-4462](http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-4462):
+ `lib/Locale/Po4a/Po.pm` in po4a before 0.32 allows local users to
+ overwrite arbitrary files via a symlink attack on the
+ gettextization.failed.po temporary file.
+
+**FIXME**: check whether this plugin would have been a possible attack
+vector to exploit these vulnerabilities.
+
+Depending on my mood, the lack of found security issues can either
+indicate that there are none, or reveal that no-one ever bothered to
+find (and publish) them.
+
+### PO file features
+
+Can any sort of directives be put in po files that will cause mischief
+(ie, include other files, run commands, crash gettext, whatever)?
+
+> No [documented](http://www.gnu.org/software/gettext/manual/gettext.html#PO-Files)
+> directive is supposed to do so. [[--intrigeri]]
+
+### Running po4a on untrusted content
+
+Are there any security issues on running po4a on untrusted content?
+
+To say the least, this issue is not well covered, at least publicly:
+
+- the documentation does not talk about it;
+- grep'ing the source code for `security` or `trust` gives no answer.
+
+On the other hand, a po4a developer answered my questions in
+a convincing manner, stating that processing untrusted content was not
+an initial goal, and analysing in detail the possible issues.
+
+#### Already checked
+
+- the core (`Po.pm`, `Transtractor.pm`) should be safe
+- po4a source code was fully checked for other potential symlink
+ attacks, after discovery of one such issue
+- the only external program run by the core is `diff`, in `Po.pm` (in
+ parts of its code we don't use)
+- `Locale::gettext`: only used to display translated error messages
+- Nicolas François "hopes" `DynaLoader` is safe, and has "no reason to
+ think that `Encode` is not safe"
+- Nicolas François has "no reason to think that `Encode::Guess` is not
+ safe". The po plugin nevertheless avoids using it by defining the
+ input charset (`file_in_charset`) before asking `Transtractor` to
+ read any file. NB: this hack depends on po4a internals to stay
+ the same.
+
+#### To be checked
+
+##### Locale::Po4a modules
+
+The modules we want to use have to be checked, as not all are safe
+(e.g. the LaTeX module's behaviour is changed by commands included in
+the content); they may use regexps generated from the content.
+
+`Chooser.pm` only loads the plugin we tell it too: currently, this
+means the `Text` module only.
+
+`Text` module (I checked the CVS version):
+
+- it does not run any external program
+- only `do_paragraph()` builds regexp's that expand untrusted
+ variables; they seem safe to me, but someone more expert than me
+ will need to check. Joey?
+
+ > Freaky code, but seems ok due to use of `quotementa`.
+
+##### Text::WrapI18N
+
+`Text::WrapI18N` can cause DoS (see the
+[Debian bug #470250](http://bugs.debian.org/470250)), but it is
+optional and we do not need the features it provides.
+
+It is loaded if available by `Locale::Po4a::Common`; looking at the
+code, I'm not sure we can prevent this at all, but maybe some symbol
+table manipulation tricks could work; overriding
+`Locale::Po4a::Common::wrapi18n` may be easier. I'm no expert at all
+in this field. Joey? [[--intrigeri]]
+
+> Update: Nicolas François suggests we add an option to po4a to
+> disable it. It would do the trick, but only for people running
+> a brand new po4a (probably too late for Lenny). Anyway, this option
+> would have to take effect in a `BEGIN` / `eval` that I'm not
+> familiar with. I can learn and do it, in case no Perl wizard
+> volunteers to provide the po4a patch. [[--intrigeri]]
+
+>> That doesn't really need to be in a BEGIN. This patch moves it to
+>> `import`, and makes this disable wrap18n:
+>> `use Locale::Po4a::Common q{nowrapi18n}` --[[Joey]]
+
+<pre>
+--- /usr/share/perl5/Locale/Po4a/Common.pm 2008-07-21 14:54:52.000000000 -0400
++++ Common.pm 2008-11-11 18:27:34.000000000 -0500
+@@ -30,8 +30,16 @@
+ use strict;
+ use warnings;
+
+-BEGIN {
+- if (eval { require Text::WrapI18N }) {
++sub import {
++ my $class=shift;
++ my $wrapi18n=1;
++ if ($_[0] eq 'nowrapi18n') {
++ shift;
++ $wrapi18n=0;
++ }
++ $class->export_to_level(1, $class, @_);
++
++ if ($wrapi18n && eval { require Text::WrapI18N }) {
+
+ # Don't bother determining the wrap column if we cannot wrap.
+ my $col=$ENV{COLUMNS};
+</pre>
-This should not be too hard using gettext tools. If this is
-implemented as a
-[HTML::Template](http://search.cpan.org/search?mode=dist&query=HTML%3A%3ATemplate)
-loop, a page using it should depend on any "master" and "slave" pages
-whose status is being displayed.
+##### Term::ReadKey
-If it's not too heavy to compute, this status data may be made
-available in the `OTHERLANGUAGES` template loop; else, a dedicated
-loop would be needed.
+`Term::ReadKey` is not a hard dependency in our case, *i.e.* po4a
+works nicely without it. But the po4a Debian package recommends
+`libterm-readkey-perl`, so it will probably be installed on most
+systems using the po plugin.
+
+If `$ENV{COLUMNS}` is not set, `Locale::Po4a::Common` uses
+`Term::ReadKey::GetTerminalSize()` to get the terminal size. How safe
+is this?
+
+Part of `Term::ReadKey` is written in C. Depending on the runtime
+platform, this function use ioctl, environment, or C library function
+calls, and may end up running the `resize` command (without
+arguments).
+
+IMHO, using Term::ReadKey has too far reaching implications for us to
+be able to guarantee anything wrt. security. Since it is anyway of no
+use in our case, I suggest we define `ENV{COLUMNS}` before loading
+`Locale::Po4a::Common`, just to be on the safe side. Joey?
+[[--intrigeri]]
+
+> Update: adding an option to disable `Text::WrapI18N`, as Nicolas
+> François suggested, would as a bonus disable `Term::ReadKey`
+> as well. [[--intrigeri]]
-Automatic PO files update
--------------------------
+### msgmerge
+
+`refreshpofiles()` runs this external program. A po4a developer
+answered he does "not expect any security issues from it".
+
+### Fuzzing input
+
+I was not able to find any public information about gettext or po4a
+having been tested with a fuzzing program, such as `zzuf` or `fusil`.
+Moreover, some gettext parsers seem to be quite
+[easy to crash](http://fusil.hachoir.org/trac/browser/trunk/fuzzers/fusil-gettext),
+so it might be useful to bang msgmerge/po4a's heads against such
+a program in order to easily detect some of the most obvious DoS.
+[[--intrigeri]]
+
+> po4a was not fuzzy-tested, but according to one of its developers,
+> "it would be really appreciated". [[--intrigeri]]
+
+Test conditions:
+
+- a 21M file containing 100 concatenated copies of all the files in my
+ `/usr/share/common-licenses/`; I had no existing PO file or
+ translated versions at hand, which renders these tests
+ quite incomplete.
+- po4a was the Debian 0.34-2 package; the same tests were also run
+ after replacing the `Text` module with the CVS one (the core was not
+ changed in CVS since 0.34-2 was released), without any significant
+ difference in the results.
+- Perl 5.10.0-16
+
+#### po4a-gettextize
+
+`po4a-gettextize` uses more or less the same po4a features as our
+`refreshpot` function.
+
+Without specifying an input charset, zzuf'ed `po4a-gettextize` quickly
+errors out, complaining it was not able to detect the input charset;
+it leaves no incomplete file on disk.
+
+So I had to pretend the input was in UTF-8, as does the po plugin.
+
+Two ways of crashing were revealed by this command-line:
+
+ zzuf -vc -s 0:100 -r 0.1:0.5 \
+ po4a-gettextize -f text -o markdown -M utf-8 -L utf-8 \
+ -m LICENSES >/dev/null
+
+They are:
+
+ Malformed UTF-8 character (UTF-16 surrogate 0xdcc9) in substitution iterator at /usr/share/perl5/Locale/Po4a/Po.pm line 1443.
+ Malformed UTF-8 character (fatal) at /usr/share/perl5/Locale/Po4a/Po.pm line 1443.
+
+and
+
+ Malformed UTF-8 character (UTF-16 surrogate 0xdcec) in substitution (s///) at /usr/share/perl5/Locale/Po4a/Po.pm line 1443.
+ Malformed UTF-8 character (fatal) at /usr/share/perl5/Locale/Po4a/Po.pm line 1443.
+
+Perl seems to exit cleanly, and an incomplete PO file is written on
+disk. I not sure whether if this is a bug in Perl or in `Po.pm`.
+
+> It's fairly standard perl behavior when fed malformed utf-8. As long as it doesn't
+> crash ikiwiki, it's probably acceptable. Ikiwiki can do some similar things itself when fed malformed utf-8 (doesn't crash tho) --[[Joey]]
+
+#### po4a-translate
+
+`po4a-translate` uses more or less the same po4a features as our
+`filter` function.
+
+Without specifying an input charset, same behaviour as
+`po4a-gettextize`, so let's specify UTF-8 as input charset as of now.
+
+ zzuf -cv \
+ po4a-translate -d -f text -o markdown -M utf-8 -L utf-8 \
+ -k 0 -m LICENSES -p LICENSES.fr.po -l test.fr
+
+... prints tons of occurences of the following error, but a complete
+translated document is written (obviously with some weird chars
+inside):
-Committing changes to a "master" page must:
+ Use of uninitialized value in string ne at /usr/share/perl5/Locale/Po4a/TransTractor.pm line 854.
+ Use of uninitialized value in string ne at /usr/share/perl5/Locale/Po4a/TransTractor.pm line 840.
+ Use of uninitialized value in pattern match (m//) at /usr/share/perl5/Locale/Po4a/Po.pm line 1002.
-1. update the POT file and the PO files for the supported languages;
- this is done in the `needsbuild` hook; the updated PO files must
- then be put under version control
+While:
-2. trigger a refresh of the corresponding HTML slave pages: this is
- achieved by making any "slave" page dependent on the corresponding
- "master" page, in the `needsbuild` hook.
+ zzuf -cv -s 0:10 -r 0.001:0.3 \
+ po4a-translate -d -f text -o markdown -M utf-8 -L utf-8 \
+ -k 0 -m LICENSES -p LICENSES.fr.po -l test.fr
-Also, when the plugin has just been enabled, all the needed POT and PO
-files have to be created.
+... seems to lose the fight, at the `readpo(LICENSES.fr.po)` step,
+against some kind of infinite loop, deadlock, or any similar beast.
+It does not seem to eat memory, though.
-UI consistency: rename "Edit" button on slave pages
----------------------------------------------------
+Whatever format module is used does not change anything. This is thus
+probably a bug in po4a's core or in a lib it depends on.
-It may be surprising to some, after having pressed *Edit* on a wiki
-page, to end up editing a strange looking PO file. The *Edit* button
-displayed on "slave" pages must therefore be renamed *Improve
-translation* .
+The sub `read`, in `TransTractor.pm`, seems to be a good debugging
+starting point.
-Pages selection depending on language
--------------------------------------
+#### msgmerge
-To improve user navigation in a multi-lingual wiki, site developers
-must be enabled to write:
+`msgmerge` is run in our `refreshpofiles` function. I did not manage
+to crash it with `zzuf`.
- \[[!map pages="dev/* and lang(LL)" feeds="no"]]
+gettext/po4a rough corners
+--------------------------
- \[[!map pages="dev/* and currentlang()" feeds="no"]]
+- fix infinite loop when synchronizing two ikiwiki (when checkouts
+ live in different directories): say bla.fr.po has been updated in
+ repo2; pulling repo2 from repo1 seems to trigger a PO update, that
+ changes bla.fr.po in repo1; then pushing repo1 to repo2 triggers
+ a PO update, that changes bla.fr.po in repo2; etc.; quickly fixed in
+ `629968fc89bced6727981c0a1138072631751fee`, by disabling references
+ in Pot files. Using `Locale::Po4a::write_if_needed` might be
+ a cleaner solution. (warning: this function runs the external
+ `diff` program, have to check security)
+- new translations created in the web interface must get proper
+ charset/encoding gettext metadata, else the next automatic PO update
+ removes any non-ascii chars; possible solution: put such metadata
+ into the Pot file, and let it propagate; should be fixed in
+ `773de05a7a1ee68d2bed173367cf5e716884945a`, time will tell.
+
+Better links
+------------
+
+### Page title in links
+
+To use the page titles set with the [[meta|plugins/meta]] plugin when
+rendering links would be very much nicer, than the current
+"filename.LL" format. This is actually a duplicate for
+[[bugs/pagetitle_function_does_not_respect_meta_titles]].
+
+Going to work on this in my `meta` branch.
+
+### Translation status in links
+
+See [[contrib/po]].
+
+### Backlinks
+
+They are not updated when the source page changes (e.g. meta title).
+
+Page formats
+------------
+
+Markdown is well supported, great, but what about others?
+
+The [[po|plugins/po]] uses `Locale::Po4a::Text` for every page format;
+this can be expected to work out of the box with most other wiki-like
+formats supported by ikiwiki. Some of their ad-hoc syntax might be
+parsed in a strange way, but the worst problems I can imagine would be
+wrapping issues; e.g. there is code in po4a dedicated to prevent
+re-wrapping the underlined Markdown headers.
+
+While it would be easy to better support formats such as [[html]] or
+LaTeX, by using for each one the dedicated po4a module, this can be
+problematic from a security point of view.
+
+**TODO**: test the more popular formats and write proper documentation
+about it.
Translation quality assurance
-----------------------------
-Modifying a PO file via the CGI must only be allowed if the new
-version is a valid PO file. As a bonus, check that it provides a more
+Modifying a PO file via the CGI must be forbidden if the new version
+is not a valid PO file. As a bonus, check that it provides a more
complete translation than the existing one.
A new `cansave` type of hook would be needed to implement this.
Note: committing to the underlying repository is a way to bypass
this check.
-Translating online
-------------------
+Creating new pages on the web
+-----------------------------
+
+See [[contrib/po|contrib/po]].
+
+Renaming pages
+--------------
+
+- Renaming a translation should be forbidden.
+
+Robustness tests
+----------------
+
+### Disabling the plugin
+
+- enabling the plugin with `po_translatable_pages` set
+- enabling the plugin without `po_translatable_pages` set: **OK**
+- disabling the plugin: **OK**
+
+### Changing the plugin config
+
+- adding existing pages to `po_translatable_pages`: **OK**
+- removing existing pages from `po_translatable_pages`: **OK**
+- adding a language to `po_slave_languages`: **OK**
+- removing a language from `po_slave_languages`: **OK**
+- changing `po_master_language`: **OK**
+- replacing `po_master_language` with a language previously part of
+ `po_slave_languages`: needs two rebuilds, but **OK** (this is quite
+ a perverse test actually)
+
+### Creating pages
-As PO is a wiki page type, we already have an online PO editor, that
-is ikiwiki's CGI.
+- creating a master page via RCS: **OK**
+- creating a master page via CGI: **OK**
-A message-by-message interface could also be implemented at some
-point; a nice way to do offline translation work (without VCS access)
-still has to be offered, though.
+### Deleting pages
-Translating offline without VCS access
---------------------------------------
+- removing a master page via RCS: **OK**
+- removing a translation via RCS: **OK**
+- removing a master page via CGI: **OK**
+- removing a translation via CGI: **OK**
-The following workflow should be made possible for translators without
-VCS access who need to edit the PO files in another editor than a web
-browser:
+### Renaming pages
-- download the page's PO file
-- use any PO editor to update the translation
-- upload the updated PO file
+- renaming a master page via RCS: **OK** (but the old translations
+ are lost, because not all RCS track file renaming)
+- renaming a master page and its translations via RCS: **OK**
+- renaming a master page via CGI: **OK**
+- renaming a translation via RCS
+- renaming a translation via CGI
-Implementation note: a generic mechanism to upload a page's source is
-needed: it's only an alternative way to allow saving a the modified
-page's source with the CGI.
+### Misc
-### Short-term workflow
+- general test with `usedirs` disabled: **OK**
+- general test with `indexpages` enabled
+- general test with `po_link_to=default`
-A possible workaround is:
+Documentation
+-------------
-- pretend to edit the PO file online
-- copy the PO file content from the textarea
-- cancel the edit
-- paste the content into a local file.
-- edit the local file in any PO editor
-- pretend to edit the PO file online
-- paste the modified local file's content into the edit textarea
-- save
+Maybe write separate documentation depending on the people it targets:
+translators, wiki administrators, hackers. This plugin may be complex
+enough to deserve this.