Importing fixtures fails when GoogleI18n used with "Couldn't create collection index. Record field 'lang' was null."

There's a problem with Doctrine_Data_Import. When trying to load a fixture record with translations, and GoogleI18n (or similar) instead of I18n is used (via actAs()), the following crash happens:
Couldn't create collection index. Record field 'lang' was null.

#0 /Users/argasek/Sites/fwm/library/doctrine/Doctrine/Access.php(131): Doctrine_Collection->add(Object(Fwm_Shop_Catalog_CategoryTranslation))
#1 /Users/argasek/Sites/test/library/doctrine/Doctrine/Data/Import.php(241): Doctrine_Access->offsetSet(NULL, Object(Test_Shop_Catalog_CategoryTranslation))
#2 /Users/argasek/Sites/test/library/doctrine/Doctrine/Data/Import.php(335): Doctrine_Data_Import->_processRow('(catalog_catego...', Array)
#3 /Users/argasek/Sites/test/library/doctrine/Doctrine/Data/Import.php(118): Doctrine_Data_Import->_loadData(Array)
#4 /Users/argasek/Sites/test/library/doctrine/Doctrine/Data.php(222): Doctrine_Data_Import->doImport(false)
#5 /Users/argasek/Sites/test/library/doctrine/Doctrine/Core.php(1011): Doctrine_Data->importData('/Users/argasek/...', 'yml', Array, false)
#6 /Users/argasek/Sites/test/library/doctrine/Doctrine/Task/LoadData.php(43): Doctrine_Core::loadData('/Users/argasek/...', false)
#7 /Users/argasek/Sites/test/library/doctrine/Doctrine/Cli.php(516): Doctrine_Task_LoadData->execute()
#8 /Users/argasek/Sites/test/library/doctrine/Doctrine/Cli.php(498): Doctrine_Cli->executeTask(Object(Doctrine_Task_LoadData), Array)
#9 /Users/argasek/Sites/test/library/doctrine/Doctrine/Cli.php(452): Doctrine_Cli->_run(Array)
#10 /Users/argasek/Sites/test/scripts/doctrine-cli.php(29): Doctrine_Cli->run(Array)
#11

I have narrowed down the problem to the line 135 of Doctrine/Data/Import.php, ie.

if ($table->hasRelation($key) && is_array($value) && ! $table->hasTemplate('Doctrine_Template_I18n')) {

In case of GoogleI18n, $table->hasTemplate('Doctrine_Template_I18n') returns false.

I have no idea how to patch this in a sane way. Adding another condition (&& ! $table->hasTemplate('Doctrine_Template_GoogleI18n') serves well as a workaround, but such condition would be required for any class similar to Doctrine_Template_GoogleI18n. I guess the condition should check if it's a Doctrine_Template_I18n template or any template iherited from this class?...