Wikimedia Bugzilla is closed!

Also seen at https://integration.wikimedia.org/ci/job/mwext-Flow-testextension/965/console

01:51:47 1) Flow\Tests\Collection\PostCollectionTest::testGetFirstRevision
01:51:47 Failed asserting that false is true.
01:51:47 
01:51:47 /srv/ssd/jenkins-slave/workspace/mwext-Flow-testextension/src/extensions/Flow/tests/phpunit/Collection/PostCollectionTest.php:90
01:51:47 /srv/ssd/jenkins-slave/workspace/mwext-Flow-testextension/src/tests/phpunit/MediaWikiTestCase.php:141
01:51:47 

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The exact failure point changes, but is always about the collection's in one way or another

added to backlog: https://trello.com/c/IxkAazu4

Was able to reproduce by booting a 12.04 instance in labs and using the jenkins repositories.  process is roughly(from a newly booted 12.04 labs instance) as root:

    mkdir -p /srv/deployment/integration/
    cd /srv/deployment/integration/
    git clone https://gerrit.wikimedia.org/r/p/integration/jenkins slave-scripts
    git clone https://gerrit.wikimedia.org/r/p/integration/phpunit
    mkdir -p /srv/ssd/jenkins-slave/tmpfs/mwext-Flow-testextension
    cd /srv/ssd/jenkins-slave/tmpfs/mwext-Flow-testextension
    git clone https://gerrit.wikimedia.org/r/p/mediawiki/core src
    cd src
    git clone https://gerrit.wikimedia.org/r/p/mediawiki/vendor
    cd extensions
    git clone https://gerrit.wikimedia.org/r/p/mediawiki/extensions/Flow
    git clone https://gerrit.wikimedia.org/r/p/mediawiki/extensions/Mantle
    cd /srv/ssd/jenkins-slave/tmpfs/mwext-Flow-testextension
    export WORKSPACE=/srv/ssd/jenkins-slave/tmpsfs/mwext-Flow-testextension
    /srv/deployment/integration/slave-scripts/bin/mw-install-sqlite.sh
    /srv/deployment/integration/slave-scripts/bin/mw-apply-settings.sh
    /srv/deployment/integration/slave-scripts/bin/mw-run-update-script.sh

Finally you can run the tests a few times, you could use this script:

    /srv/deployment/integration/slave-scripts/bin/mw-run-phpunit-allexts.sh

But to replicate you only need to run the tests:

    cd /srv/ssd/jenkins-slave/tmpfs/mwext-Flow-testextension/src/tests/phpunit
    php phpunit.php \
        --with-phpunitdir /srv/deployment/integration/phpunit/vendor/phpunit/phpunit \
        --testsuite extensions \
        --filter Permission

Since its an intermittent failure you need to run it in a loop

    for i in {1..50};do php phpunit.php ...;done

Tried same process on 14.04 and this problem doesn't occur, almost certainly this will all happen on 12.04 without the jenkins scripts to set things up, but i havn't tested as they are rather convenient.


Still not sure whats causing the failure, but reproduction should help

When AbstractCollection::getAllRevisions() is called it runs a find query with sorting options.  On the failed tests these sorting options are not being respected and the revisions are in the wrong order.

Still not sure how to fix, getting closer but its bed time :)

Heres a narrower reproduction case:

    <?php 

    use Flow\Model\UUID;

    include __DIR__ . '/../../maintenance/commandLine.inc';
    include __DIR__ . '/includes/Model/UUID.php';

    $dbw = wfGetDB( DB_MASTER );
    $dbw->query( 'CREATE TEMP TABLE some_test ( workflow_id binary(11) not null, PRIMARY KEY (workflow_id))' );

    $dbw->insert( 'some_test', array(
      array (
        'workflow_id' => UUID::hex2bin( UUID::alnum2hex( 's57ovj7y1hbificr' ) ),
      ),
      array (
        'workflow_id' => UUID::hex2bin( UUID::alnum2hex( 's57ovj88ycd1std7' ) ),
      ),
    ) );
    $res = $dbw->select(
        'some_test',
        array( '*' ),
        array(),
        __METHOD__,
        array( 'LIMIT' => 100, 'ORDER BY' => 'workflow_id DESC' )
    );
    foreach ( $res as $row ) {
        $row = (array)$row;
        $result[UUID::hex2alnum(UUID::bin2hex($row['workflow_id']))] = $row;
    }
    echo implode( ',', array_keys( $result ) ), "\n";
    $sorted = $result;
    krsort( $sorted );
    if ( array_keys( $result ) !== array_keys( $sorted ) ) {
        echo "\nWrong order, received ascending workflow ids\n";
    }


On 12.04 with sqlite it returns this:

    s57ovj7y1hbificr,s57ovj88ycd1std7

    Wrong order, received ascending workflow ids

On a vagrant instance(14.04 w/mysql):

    s57ovj88ycd1std7,s57ovj7y1hbificr


So the problem is that for some set of ID's, the sqlite in 12.04 fails to sort them properly

So it turns out this bug only happens when our UUID's contain a null byte.  The full and complete value is returned from a query, but it gets sorted wrong.  

There is a bugfix in DatabaseSqlite::addQuotes() that says sqlite truncates data with null bytes unless quoted properly.  My best guess is that although we inserted the data correctly(thanks to that bugfix), the truncation was still occurring within sqlite's sorting algo.

Change 170356 had a related patch set uploaded by EBernhardson:
Fix intermittent test failures on 12.04

https://gerrit.wikimedia.org/r/170356

Change 170396 had a related patch set uploaded by EBernhardson:
Always decode Blob objects from Database::decodeBlob

https://gerrit.wikimedia.org/r/170396

Change 170356 merged by jenkins-bot:
Fix intermittent test failures on 12.04

https://gerrit.wikimedia.org/r/170356

Change 171999 had a related patch set uploaded by EBernhardson:
Doc: Document problem sorting inserted data

https://gerrit.wikimedia.org/r/171999

Change 171999 merged by jenkins-bot:
Doc: Document problem sorting inserted data

https://gerrit.wikimedia.org/r/171999