Warnings with E_ALL

I'm running my PHP dev enviroment with E_ALL defined on error reporting. This is cause I think warnings also give meaningful information. However when using Drush it gets kind of annoying. Some warnings are always displayed and I think the small issues could be fixed really quick.

The warnings are the following:

Notice: Undefined variable: options in /usr/local/drush/includes/command.inc on line 71

Notice: Undefined index:  custom in /usr/local/drush/includes/context.inc on line 93

Notice: Undefined index:  path in /usr/local/drush/includes/environment.inc on line 417

I wanted to submit a patch, but I was only able to fix the first one in command.inc.