Commented Issue: request more results than exists - null reference exception [2526]

If try to return more results than exists, can end up getting no results and a null reference exception


I was trying to get followers and a bug in my code was requesting a hard limit of 20,000 instead of the number of followers of a user


The responses were coming in

```
{"ids":[....removed.....],"next_cursor":1494012216769213740,"next_cursor_str":"1494012216769213740","previous_cursor":-1494022639035402884,"previous_cursor_str":"-1494022639035402884"}

{"ids":[],"next_cursor":0,"next_cursor_str":"0","previous_cursor":-1,"previous_cursor_str":"-1"}

{"ids":[],"next_cursor":0,"next_cursor_str":"0","previous_cursor":-1,"previous_cursor_str":"-1"}

{"ids":[],"next_cursor":0,"next_cursor_str":"0","previous_cursor":-1,"previous_cursor_str":"-1"}
....
```
As no more responses were found in the first call, the code just kept looping until it hit a rate limiting and then as per my other issue submission ends up as a null reference error


Whilst stepping through this, it appear my rate limiting got dropped from 180 per 15 minutes, to 15 per 15 minute, which was low enough to trigger this error almost everytime
Comments: Associated with changeset 42505: Version 0.9.6.0
- Improved cursor query accessor to check for special case described in the issue