drush-ops/drush — pull request #163 by smk (2013-09-27 11:35:46+00:00)
Title: array_key_exists() expects parameter 2 to be array, null given in engines.inc

This fixes an array_key_exists() warning in case no default engine implementation has been specified in hook_drush_engine_type_info(), causing drush_merge_engine_data() trying to use NULL as array key.