UcAddressesAddressBook::loadStatic() doesn't check if loading address was successful

Problem/Motivation

There is a bug in the method loadStatic() of the UcAddressesAddressBook class. When loading a single address using the method loadAddress() (which calls loadStatic()), an error (notice) will occur if the address couldn't be found in the database.
Currently, nowhere in the module this method is called, so this error should never occur when no modules are used that extend Ubercart Addresses. However, other modules may call this method and it's likely it will be called too by Ubercart Addresses itself when Entity API integration is completed (because entities are usually loaded by giving the ID only, and the loadAddress() method should only be used when the address ID is known, but not the user ID).

Affected versions

This is a bug in both 7.x-1.x and 6.x-2.x.

Proposed resolution

In the method loadStatic(), check if loading from the database was successful. Implement/adjust an automated test to ensure that the bug is fixed.

Remaining tasks

• Implement fix for the bug.
• Implement/adjust an automated test to ensure that the bug is fixed.

User interface changes

None.

API changes

None.

Patch will follow.