gettext, using [po4a](http://po4a.alioth.debian.org/).
It depends on the Perl `Locale::Po4a::Po` library (`apt-get install po4a`).
+As detailed bellow in the security section, `po4a` is subject to
+denial-of-service attacks before version 0.35.
[[!toc levels=2]]
translate `bla/page.mdwn` into French; if `usedirs` is enabled, it is
rendered as `bla/page/index.fr.html`, else as `bla/page.fr.html`
+(In)Compatibility
+=================
+
+This plugin does not support the `indexpages` mode. If you don't know
+what it is, you probably don't care.
+
Configuration
=============
languages, such as:
po_slave_languages => { 'fr' => 'Français',
- 'es' => 'Castellano',
+ 'es' => 'Español',
'de' => 'Deutsch',
}
Internal links
--------------
+### Links targets
+
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
+#### Default linking behavior
If `po_link_to` is unset, or set to `default`, ikiwiki's default
linking behavior is preserved: `\[[destpage]]` links to the master
language's page.
-### Link to current language
+#### 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
+* `foo/destpage/index.LL.html` if `usedirs` is enabled
+* `foo/destpage.LL.html` if `usedirs` is disabled
-### Link to negotiated language
+#### Link to negotiated language
If `po_link_to` is set to `negotiated`, `\[[page]]` links to the
negotiated preferred language, *i.e.* `foo/page/`.
(In)compatibility notes:
-- if `usedirs` is disabled, it does not make sense to set `po_link_to`
+* 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
+* if the web server does not support Content Negotiation, setting
`po_link_to` to `negotiated` will produce a unusable website.
-
Server support
==============
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.
+
+Add 'Options MultiViews' to the wiki directory's configuration in Apache.
When `usedirs` is enabled, one has to set `DirectoryIndex index` for
the wiki context.
language code) for the wiki context can help to ensure
`bla/page/index.en.html` is served as `Content-Language: LL`.
+For details, see [Apache's documentation](http://httpd.apache.org/docs/2.2/content-negotiation.html).
+
lighttpd
--------
Templates
---------
+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.
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">"><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):
-
-- `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
+An example of its use can be found in the default
+`templates/page.tmpl`. In case you want to customize it, the following
+variables are available inside the loop (for every page in):
+
+* `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
### Display the current translation status
The `PERCENTTRANSLATED` variable is set to the translation
-completeness, expressed in percent, on "slave" pages.
-
-One can use it this way:
-
- <TMPL_IF NAME="ISTRANSLATION">
- <div id="percenttranslated">
- <TMPL_VAR NAME="PERCENTTRANSLATED">
- </div>
- </TMPL_IF>
+completeness, expressed in percent, on "slave" pages. It is used by
+the default `templates/page.tmpl`.
Additional PageSpec tests
-------------------------
been declared as being translatable, the needed POT and PO files are
created, and the PO files are checked into version control.
-Discussion pages
-----------------
+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
-----------
If [[tips/untrusted_git_push]] is setup, one can edit the PO files in one's
preferred `$EDITOR`, without needing to be online.
-TODO
-====
-
-Security checks
----------------
-
-### Security history
-
-The only past security issues I could find in GNU gettext and po4a
-are:
-
-- [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.
+Markup languages support
+------------------------
-**FIXME**: check whether this plugin would have been a possible attack
-vector to exploit these vulnerabilities.
+[[Markdown|mdwn]] is well supported. Some other markup languages supported
+by ikiwiki mostly work, but some pieces of syntax are not rendered
+correctly on the slave pages:
-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.
+* [[reStructuredText|rst]]: anonymous hyperlinks and internal
+ cross-references
+* [[wikitext]]: conversion of newlines to paragraphs
+* [[creole]]: verbatim text is wrapped, tables are broken
+* [[html]] and LaTeX: not supported yet; the dedicated po4a modules
+ could be used to support them, but they would need a security audit
+* other markup languages have not been tested.
-### PO file features
+Security
+========
-Can any sort of directives be put in po files that will cause mischief
-(ie, include other files, run commands, crash gettext, whatever)?
+[[po/discussion]] contains a detailed security analysis of this plugin
+and its dependencies.
-> No [documented](http://www.gnu.org/software/gettext/manual/gettext.html#PO-Files)
-> directive is supposed to do so. [[--intrigeri]]
+When using po4a older than 0.35, it is recommended to uninstall
+`Text::WrapI18N` (Debian package `libtext-wrapi18n-perl`), in order to
+avoid a potential denial of service.
-### Running po4a on untrusted content
+TODO
+====
-Are there any security issues on running po4a on untrusted content?
+Better links
+------------
-To say the least, this issue is not well covered, at least publicly:
+Once the fix to
+[[bugs/pagetitle_function_does_not_respect_meta_titles]] from
+[[intrigeri]]'s `meta` branch is merged into ikiwiki upstream, the
+generated links' text will be optionally based on the page titles set
+with the [[meta|plugins/meta]] plugin, and will thus be translatable.
+It will also allow displaying the translation status in links to slave
+pages. Both were implemented, and reverted in commit
+ea753782b222bf4ba2fb4683b6363afdd9055b64, which should be reverted
+once [[intrigeri]]'s `meta` branch is merged.
-- the documentation does not talk about it;
-- grep'ing the source code for `security` or `trust` gives no answer.
+An integration branch, called `meta-po`, merges [[intrigeri]]'s `po`
+and `meta` branches, and thus has this additional features.
-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.
+Language display order
+----------------------
-#### Already checked
+Jonas pointed out that one might want to control the order that links to
+other languages are listed, for various reasons. Currently, there is no
+order, as `po_slave_languages` is a hash. It would need to be converted
+to an array to support this. (If twere done, twere best done quickly.)
+--[[Joey]]
-- 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.
+Pagespecs
+---------
-#### To be checked
+I was suprised that, when using the map directive, a pagespec of "*"
+listed all the translated pages as well as regular pages. That can
+make a big difference to an existing wiki when po is turned on,
+and seems generally not wanted.
+(OTOH, you do want to match translated pages by
+default when locking pages.) --[[Joey]]
-##### Locale::Po4a modules
+Edit links on untranslated pages
+--------------------------------
-- 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; we
- currently only use the `Text` module
-- the `Text` module does not run any external program
-- check that no module is loaded by `Chooser.pm`, when we tell it to
- load the `Text` one
-- `nsgmls` is used by `Sgml.pm`
+If a page is not translated yet, the "translated" version of it
+displays wikilinks to other, existing (but not yet translated?)
+pages as edit links, as if those pages do not exist.
-##### Text::WrapI18N
+That's really confusing, especially as clicking such a link
+brings up an edit form to create a new, english page.
-`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.
+This is with po_link_to=current or negotiated. With default, it doesn't
+happen..
-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]]
+Also, this may only happen if the page being linked to is coming from an
+underlay, and the underlays lack translation to a given language.
+--[[Joey]]
-##### Term::ReadKey
+Double commits of po files
+--------------------------
-`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.
+When adding a new english page, the po files are created, committed,
+and then committed again. The second commit makes this change:
-If `$ENV{COLUMNS}` is not set, `Locale::Po4a::Common` uses
-`Term::ReadKey::GetTerminalSize()` to get the terminal size. How safe
-is this?
+ -"Content-Type: text/plain; charset=utf-8\n"
+ -"Content-Transfer-Encoding: ENCODING"
+ +"Content-Type: text/plain; charset=UTF-8\n"
+ +"Content-Transfer-Encoding: ENCODING\n"
-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).
+Same thing happens when a change to an existing page triggers a po file
+update. --[[Joey]]
-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]]
-
-### msgmerge
+Ugly messages with empty files
+------------------------------
-`refreshpofiles()` runs this external program. A po4a developer
-answered he does "not expect any security issues from it".
+If there are empty .mdwn files, the po plugin displays some ugly messages.
-### Fuzzing input
+Translation of directives
+-------------------------
-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]]
+If a translated page contains a directive, it may expand to some english
+text, or text in whatever single language ikiwiki is configured to "speak".
-> po4a was not fuzzy-tested, but according to one of its developers,
-> "it would be really appreciated". [[--intrigeri]]
+Maybe there could be a way to switch ikiwiki to speaking another language
+when building a non-english page? Then the directives would get translated.
-gettext/po4a rough corners
---------------------------
+Documentation
+-------------
-- 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.
-
-Misc. improvements
-------------------
-
-### page titles
-
-Use nice page titles from meta plugin in links, as inline already
-does. This is actually a duplicate for
-[[bugs/pagetitle_function_does_not_respect_meta_titles]], which might
-be fixed by something like [[todo/using_meta_titles_for_parentlinks]].
-
-### source files format
-
-Markdown is supported, great, but what about others? The set of file
-formats supported both in ikiwiki and po4a probably is greater than
-`{markdown}`. Warning: the po4a modules are the place where one can
-expect security issues.
-
-Translation quality assurance
------------------------------
-
-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.
+Maybe write separate documentation depending on the people it targets:
+translators, wiki administrators, hackers. This plugin may be complex
+enough to deserve this.