`<UnnamedApp>` or `<Unknown>` sounds good for any of these error cases.

Note that this 'bug' was found via a securiy-oriented static analysis; I do not have a real world test case, but it is theoretically possible for getCString:maxLength:encoding: to return NO if the string isn't actually valid UTF8 or if the buffer were too small (which shouldn't happen since we just allocated it to the appropriate size).