secur32: Take schannel backend capabilities into account when configuring enabled protocols.

[Ken Thomases]

On Apr 11, 2013, at 8:49 AM, Jacek Caban wrote:

> On 04/10/13 16:16, Ken Thomases wrote:
>> However, Apple's guidance on using weak linking says that you must explicitly compare against NULL.  They don't quite say that testing the symbol as a standalone boolean expression won't work, but they do say that using negation (the ! operator) isn't sufficient.
>> https://developer.apple.com/library/mac/documentation/developertools/conceptual/cross_development/Using/using.html#//apple_ref/doc/uid/20002000-SW4
>> 
>> I'm not sure what the rationale is, but I think there's a peculiarity of what the compiler thinks it knows versus what the linker actually knows.  Basically, the compiler figures there's a symbol that will be resolved (or cause a link error), so the check can be optimized away somehow.  I think.
> 
> Oh, such restriction seem to indicate a broken design of this weak
> linking... Following this is fine, through, but perhaps we should use
> nil to be sure that NULL override in winnt.h won't confuse the heuristic?

I expect that "nil" is only meaningful in Objective-C code.  I'd be surprised if there was anything special about NULL (either Apple's or Wine's), per se, but if you want an alternative that's insulated against any Wine peculiarities, I'd just use a literal "0" (zero).


>> Other than that, the patch looks good to me.
> 
> Thanks for the review.

Happy to help.

-Ken