bad paths cause fatal error

we are getting hit by some robots trying to access non-existent paths on the site. the problem is that the path is not in a valid format, so parse_url() returns FALSE and issues a warning. the warning is annoying but we can ignore it. but because it doesn't return an array, this line in path_redirect.module:

i'm not sure what you would want to do in this case, but it looks like parse_url was just being used to pull off the query and fragment values, so using a default seems to work ok:

it might be better to use preg_match to get the components instead, to avoid the warning from parse_url(), but i'm not sure what the correct regex pattern would be to do that.