Feeds error log crashes when log messages are too long

I think Feeds shouldn't translate anything that is derived from an exception message. In some case that exception message is already translated, for example in includes/FeedsSource.inc, ± line 791:

protected function acquireLock() {
  if (!lock_acquire("feeds_source_{$this->id}_{$this->feed_nid}", 60.0)) {
    throw new FeedsLockException(t('Cannot acquire lock for source @id / @feed_nid.', array('@id' => $this->id, '@feed_nid' => $this->feed_nid)));
  }
}

I tracked down two places where Feeds logs a message derived from an exception message:

1. From feeds.module, ± line 155:

   catch (Exception $e) {
     $source->log($method, $e->getMessage(), array(), WATCHDOG_ERROR);
   }
   

2. From plugins/FeedsProcessor.inc, ± line 269:

   // Something bad happened, log it.
   catch (Exception $e) {
     $state->failed++;
     drupal_set_message($e->getMessage(), 'warning');
     $message = $this->createLogMessage($e, $entity, $item);
     $source->log('import', $message, array(), WATCHDOG_ERROR);
   }
   

At the following places there are also already translated messaged logged:

• From plugins/FeedsProcessor.inc, ± line 345:
  

  foreach ($messages as $message) {
    drupal_set_message($message['message']);
    $source->log('import', $message['message'], array(), isset($message['level']) ? $message['level'] : WATCHDOG_INFO);
  }
  

• From plugins/FeedsProcessor.inc, ± line 471:
  

  $message = format_plural(
    $state->deleted,
    'Deleted @number @entity',
    'Deleted @number @entities',
    array(
      '@number' => $state->deleted,
      '@entity' => strtolower($info['label']),
      '@entities' => strtolower($info['label plural']),
    )
  );
  $source->log('clear', $message, array(), WATCHDOG_INFO);
  drupal_set_message($message);
  

Perhaps the function feeds_log() and the method FeedsSource::log() should get an extra optional parameter for whether or not the message is translatable?

Inspired by the patch from #2502419: Log messages XSS attack vector, I think we should log exception messages like this:

$source->log($method, '@exception', array('@exception' => $e->getMessage()), WATCHDOG_ERROR);

At places where for the message format_plural() is used, there should be
two $source->log() lines, one for each message. Something like this:

if ($state->deleted == 1) {
  $source->log('clear', 'Deleted @number @entity', $vars, WATCHDOG_INFO);
}
else {
  $source->log('clear', 'Deleted @number @entities', $vars, WATCHDOG_INFO);
}

Bumping to critical because these logged messages can bloat up the locales_source table.

I'm going to create a different issue for sorting out logging. We need a lot of work in that area.