ntdll: Fix SIGTRAP handling

[Alexandre Julliard]

Petr Tesarik <hat at tesarici.cz> writes:

> In my opinion, the solution is reasonable because if any application
> is really interested in the DR6 register (i.e. it is a debugger), it
> will clear the status register (DR6) anyway, since the processor never
> clears the bits and unless you clear them manually, the register gets
> pretty useless.

There are applications other than debuggers that care about debug
registers, notably copy protection code. We can't afford to do things
differently even if they sound reasonable.

> I wonder why you haven't been bothered by the fact that the current
> implementation silently drops the TF bit, which is even worse! :O

I'm sure there are bugs in the current implementation, but that's not
a reason for introducing different ones... If you find anything that
the current code is doing wrong, please provide a test case
demonstrating the bug, and I'll be more than happy to fix it (or to
accept a fix if you have one).

-- 
Alexandre Julliard
julliard at winehq.org