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Incorrect use of IsWow64Process in Cygwin sources


Please consider the following snippet from src/winsup/cygwin/wincap.cc
(wincapc::init):

  BOOL is_wow64_proc = FALSE;
  if (IsWow64Process (GetCurrentProcess (), &is_wow64_proc))
    wow64 = is_wow64_proc;
  else
    {
      ((wincaps *)this->caps)->needs_count_in_si_lpres2 = false;
      ((wincaps *)this->caps)->has_restricted_stack_args = false;
    }

If I understood correctly, the "else" block is meant to be executed on 32 bit systems, so that those flags are reset on Vista 32.

But you are testing the return value of IsWow64Process, which is only an indication that the function succeeded. For instance, it always returns true on my 32 bit system (Windows XP Home Edition). The correct return value is in the is_wow64_proc flag, you should use it.

The relevant MSDN page documenting IsWow64Process is:
http://msdn2.microsoft.com/en-us/library/ms684139(VS.85).aspx

Regards,
Cesar


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