ADVAPI32: preserve the last error value set by the CSP in CryptAcquireContext

[Mike McCormack]

Robert Shearman wrote:

>> error:
>> +    /* must preserve the last error returned by the CSP here */
>> +    r = GetLastError();
>>     if (pProv)
>>     {
>>         FreeLibrary(pProv->hModule);
>> @@ -486,6 +488,7 @@
>>     CRYPT_Free(provname);
>>     CRYPT_Free(temp);
>>     CRYPT_Free(imagepath);
>> +    SetLastError( r );
>>     return FALSE;
>> }
>>
>>
> This seems wrong. Which function is calling SetLastError? I believe 
> there was a problem a while ago with freeing bad pointers. I can't 
> remember whether a fix went in for that.
> 
> Rob

Yeah, well, something there is calling SetLastError(). We can muck round 
trying to fix it by finding which pointer is bad, but the problem can 
easily rear it's head again unless there's a comment or specific code in 
there to point out the problem.

A better fix would be to convert it to using RtlHeapAlloc() and 
RtlHeapFree() so that the last error isn't touched, and perhaps use 
LdrFreeLibrary too.

Mike