Moodle

Circular dependency in parentlanguage definition may easily lead to infinitive loops

Details

  • Type: Bug Bug
  • Status: Closed Closed
  • Priority: Critical Critical
  • Resolution: Fixed
  • Affects Version/s: 2.1.10, 2.2.9, 2.3.6, 2.4.3, 2.5
  • Fix Version/s: 2.3.7, 2.4.4
  • Component/s: Language
  • Labels:
  • Testing Instructions:
    Hide

    Testing difficulty: medium (requires direct access to moodledata)

    1. Install some language pack (let's call it 'xx')
    2. Edit $CFG->dataroot/lang/xx/langconfig.php
    3. Change/add the parent language declaration and point it to the language itself:

    $string['parentlanguage'] = 'xx';

    4. TEST: Make sure the site (e.g. the front page) is still available (it died in infinitive loop before).

    Show
    Testing difficulty: medium (requires direct access to moodledata) 1. Install some language pack (let's call it 'xx') 2. Edit $CFG->dataroot/lang/xx/langconfig.php 3. Change/add the parent language declaration and point it to the language itself: $string['parentlanguage'] = 'xx'; 4. TEST: Make sure the site (e.g. the front page) is still available (it died in infinitive loop before).
  • Affected Branches:
    MOODLE_21_STABLE, MOODLE_22_STABLE, MOODLE_23_STABLE, MOODLE_24_STABLE, MOODLE_25_STABLE
  • Fixed Branches:
    MOODLE_23_STABLE, MOODLE_24_STABLE
  • Pull from Repository:
  • Pull 2.4 Branch:
    MDL-39023-parentlang_24
  • Pull 2.4 Diff URL:
  • Pull Master Branch:
    MDL-39023-parentlang
  • Pull Master Diff URL:

Description

This was just observed at lang.moodle.org - the maintainer of he_kids language pack set the parentlanguage of it to the he_kids itself (instead of expected he). This creates circular dependency problem in string_manager::get_language_dependecies() and the site with the lang installed dies in infinitive loop hell.

Issue Links

has been marked as being related by

Bug - A problem which impairs or prevents Moodle from functioning correctly. MDLSITE-2194 html error 500 on lang.moodle.org

  • Minor - Minor loss of function where workaround is possible
  • Closed - The issue is considered finished, the resolution is correct. Issues which are closed should not be reopened.

Activity

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Permalink
Koen Roggemans added a comment -

Wow - that's a silly mistake. Probably one of the milion possibilities in how to break a Moodle site by making errors in a language pack.

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Koen Roggemans added a comment - Wow - that's a silly mistake. Probably one of the milion possibilities in how to break a Moodle site by making errors in a language pack.
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Permalink
David Mudrak added a comment -

Yeah, especially langconfig.php seems to be tricky. The other day, we were talking about how ISO codes are broken across lang packs (see MDLSITE-2191). Maybe it's time to actually start managing langconfig.php independently on other strings and manage it centrally (an by AMOS admins only, not by maintainers themselves).

Show
David Mudrak added a comment - Yeah, especially langconfig.php seems to be tricky. The other day, we were talking about how ISO codes are broken across lang packs (see MDLSITE-2191 ). Maybe it's time to actually start managing langconfig.php independently on other strings and manage it centrally (an by AMOS admins only, not by maintainers themselves).
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Permalink
Koen Roggemans added a comment -

Not all can be done by AMOS admins I'm affraid (alphabet, thousend separator, ...), but I aggree that the technical ones could do with protection and be our responsability that they are correct.

Show
Koen Roggemans added a comment - Not all can be done by AMOS admins I'm affraid (alphabet, thousend separator, ...), but I aggree that the technical ones could do with protection and be our responsability that they are correct.
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Ralf Krause added a comment - - edited

There seems to be a very important problem.

What should a language maintainer write into the field "parentlanguage" within the component "core_langconfig"? I think that the field should stay empty in the german language pack "de". If I would write de into this field than the son would be the same person as his father and the father would be the same as the grandfather.

Or should I write "en" into this field because the fallback is "en" ... every maintainer tries to get 100%

Show
Ralf Krause added a comment - - edited There seems to be a very important problem. What should a language maintainer write into the field "parentlanguage" within the component "core_langconfig"? I think that the field should stay empty in the german language pack "de". If I would write de into this field than the son would be the same person as his father and the father would be the same as the grandfather. Or should I write "en" into this field because the fallback is "en" ... every maintainer tries to get 100%
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David Mudrak added a comment -

@Ralf Krause: The correct value for the parentlanguage of 'de' is empty value as the language does not have any explicit parent language. IIRC, this string is excluded from missing strings stats in AMOS so it won't block you from reaching 100% of translated strings. Having explicit 'en' there is tolerated, too. Having 'de' there would cause the infinite loop problem (and that is what this issue is about).

Show
David Mudrak added a comment - @ Ralf Krause : The correct value for the parentlanguage of 'de' is empty value as the language does not have any explicit parent language. IIRC, this string is excluded from missing strings stats in AMOS so it won't block you from reaching 100% of translated strings. Having explicit 'en' there is tolerated, too. Having 'de' there would cause the infinite loop problem (and that is what this issue is about).
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David Mudrak added a comment -

Submitting a patch for integration. The patch reimplements the core_string_manager::get_language_dependencies() method so that potentially mis-configured language packs with circular dependencies or self dependency do not make the site unavailable. Unit tests for the expected behaviour are added.

Show
David Mudrak added a comment - Submitting a patch for integration. The patch reimplements the core_string_manager::get_language_dependencies() method so that potentially mis-configured language packs with circular dependencies or self dependency do not make the site unavailable. Unit tests for the expected behaviour are added.
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Eloy Lafuente (stronk7) added a comment -

Integrated (23, 24 & master), thanks!

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Eloy Lafuente (stronk7) added a comment - Integrated (23, 24 & master), thanks!
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Eloy Lafuente (stronk7) added a comment - - edited

unit tests passed @ CI servers

Edited, grrr, typo.

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Eloy Lafuente (stronk7) added a comment - - edited unit tests passed @ CI servers Edited, grrr, typo.
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Eloy Lafuente (stronk7) added a comment -

Passing, I've reproduced the problem without the patch and works with it applied.

Ciao

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Eloy Lafuente (stronk7) added a comment - Passing, I've reproduced the problem without the patch and works with it applied. Ciao
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Eloy Lafuente (stronk7) added a comment -

Your awesome contributions are now part of Moodle, your fav LMS out there.

Closing this as fixed.

Many thanks for all the hard work, ciao

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Eloy Lafuente (stronk7) added a comment - Your awesome contributions are now part of Moodle, your fav LMS out there. Closing this as fixed. Many thanks for all the hard work, ciao

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Dates

  • Created:
    Updated:
    Resolved: