#1416 Cocoa xception in SetVerticalScrollPos when MaxScrollPos = 0

[Mark Yen]

(Sorry about the summary, the field is length-limited)?

When the editor's MaxScrollPos() is 0, ScintillaCocoa::SetVerticalScrollPos() will happily divide topLine by it, resulting in NaN. Passing that to setVerticalScrollPosition will raise an ObjC exception and crash; the attached patch checks that case and just sets the scroll position to 0 instead.

There may be a similar case in setting the horizontal position, but I haven't confirmed it yet... Also, while I've managed to build the sample, I haven't been able to trigger the crash without the patch; I'm suspecting that it wasn't built with CoreAnimation, but I haven't confirmed it yet.

[Mark Yen]

Check MaxScrollPos() before dividing

[Neil Hodgson]

I won't be looking at this until the new year.

[Neil Hodgson]

Committed with some extra brackets for safety and changing 0f to 0.0f as 0f produced an error about an invalid octal number.