[fpc-devel] Types.IntersectRect(), probably bug or misusage VERY URGENT

[Sergei Gorelkin]

Jonas Maebe пишет:

>> With a little testing, here are two facts:
>> 1) Delphi 7 also shows this bug.
>> 2) Windows.IntersectRect() does not show it, allowing 'misuses'.
>>
>> So, whoever wrote the FPC function, must have been trying really hard 
>> to achieve bug-to-bug compatibility with Delphi... or simply copied 
>> their buggy code.
> 
> Not necessarily. It's probably a consequence of the person not seeing a 
> reason for first doing everything in a temporary variable and then 
> copying this temporary variable to the destination. Unless you 
> consciously think about the fact that const parameters may be passed by 
> reference, it's easy to make such "mistakes" (although technically, they 
> are not mistakes, but they do make it easier for people using such a 
> function to make error).
> 
Well, maybe. For me, it is rather hard to think about the opposite - that a const may be passed 
*not* by reference - due to long-term Delphi/Windows experience.

But, after all, Types.IntersectRect and surrounding stuff were introduced and are intended as WinApi 
replacement, and WinApi IntersectRect() *does* pass params by reference (they are originally PRect).
So maybe it will be still good to fix Types.IntersectRect to conform?

Regards,
Sergei