PostgreSQL: Fix tests in search test group

GROUP BY error and some others...

This should fix broken SearchBlockTests as a first start. Let's see what MySQL bot thinks...

Great, patch fixes broken SearchBlockTest and SearchPageTextTest. However while working on the remaining issues I noticed some strange random test fails because of database is locked errors. This happens namely in SearchNumberMatchingTest and SearchRankingTest as a handful of runs show.
I also run the search test group with MySQL and the same random fails show up, so it's not really PostgreSQL only. Anyway, I have no real idea how to work around that yet, so any help is welcome here ;-)

I attached the PostgreSQL and MySQL test results for review.

Drupal\Core\Database\DatabaseExceptionWrapper: SQLSTATE[HY000]: General
    error: 5 database is locked: INSERT INTO {simpletest} (test_id, test_class,
    status, message, message_group, function, line, file) VALUES (?, ?, ?, ?, ?,
    ?, ?, ?); Array
    (
        [0] => 22
        [1] => Drupal\search\Tests\SearchRankingTest
        [2] => pass
        [3] => Search ranking "sticky" order.
        [4] => Other
        [5] => Drupal\search\Tests\SearchRankingTest->testRankings()
        [6] => 134
        [7] => /var/www/core/modules/search/src/Tests/SearchRankingTest.php
    )
     in Drupal\simpletest\TestBase->assert() (line 292 of
    /var/www/core/modules/simpletest/src/TestBase.php).
    Drupal\Core\Database\Connection->query('INSERT INTO {simpletest} (test_id,
    test_class, status, message, message_group, function, line, file) VALUES (?,
    ?, ?, ?, ?, ?, ?, ?)', Array, Array)
    Drupal\Core\Database\Query\Insert->execute()
    Drupal\Core\Database\Driver\sqlite\Insert->execute()
    Drupal\simpletest\TestBase->assert(1, 'Search ranking "sticky" order.',
    'Other')
    Drupal\simpletest\TestBase->assertEqual('2', '2', 'Search ranking "sticky"
    order.')
    Drupal\search\Tests\SearchRankingTest->testRankings()
    Drupal\simpletest\TestBase->run()
    simpletest_script_run_one_test('22',
    'Drupal\search\Tests\SearchRankingTest')

Guess this could be caused by a still running cron job? I mean, search tests make often use of cron for indexing... needs investigation

I found that the 'database is locked' issue happens even outside of search test group, so that will need a separate issue. Patch still applies and passes MySQL bot so I'm setting to RTBC as it' a just single line change and does fix PG fails.

Opened #2420909: Random database is locked errors

Okay thanks @webchick! So let's wait for a search maintainer review then... Just to make sure, attaching the PostgreSQL test run log showing 100% passing tests with patch applied.

@jhodgdon, here is the actual error:

[0m    [03-Dec-2014 09:37:56 UTC] Uncaught PHP Exception
    Drupal\Core\Database\DatabaseExceptionWrapper: "SQLSTATE[42803]: Grouping
    error: 7 ERROR:  column "i.sid" must appear in the GROUP BY clause or be
    used in an aggregate function
[31mFail      Fatal erro Unknown              0 Unknown                            
[0m    LINE 3: (SELECT i.sid AS sid
[31mFail      Fatal erro Unknown              0 Unknown                            
[0m    ^" at /var/www/core/lib/Drupal/Core/Database/Driver/pgsql/Connection.php

Yes, adding the group by only within the if condition feels wrong, but if I remember right I already tried it outside but with no luck. I will try that again later and post the results.

Okay, here we go. Adding the groupBy right after! the if condition seems to work. That means we should now be save, even in case that the if condition is false...
Let's see if we pass MySQL with patch attached.

New patch based on comments from #18.

@alexpott: I have just setup a public (very simple) PostgreSQL Bot on Wednesday that runs all tests once a day. BTW, thanks for commit.