empty hook_schema() breaks _drupal_initialize_schema()

A module developer leaving hook_schema() without any return value (hence returning FALSE) will break calling code in the way that _drupal_initialize_schema() reacts to the situation. For example:

function hook_schema() {
}

The snippet above placed into a module's .install file would result in _drupal_initialize_schema() returning FALSE for that module's schema.

It is typical for a developer to leave stubs lying around while dealing with other parts of module implementation. For _drupal_initialize_schema() to NOT initialize an empty schema (passed in as FALSE) to be an array() breaks its contract.

Don't you dare 'by design' this one. ;)