[Openal-devel] Bug in openal/win/Router/alc.cpp

[Kenneth B. Russell]

I've been doing some work recently on the Java bindings for OpenAL 
project (http://joal.dev.java.net/) and have found a bug in the 
OpenAL32.dll "router" DLL. The bug is at line 484 of 
openal/win/Router/alc.cpp. Code earlier than that searches through the 
current working directory and other places for the pattern "*oal.dll" 
intending to find OpenAL implementations like (the misnamed) 
wrap_oal.dll. This inadvertently picks up JOAL's "joal.dll" in certain 
situations like when joal.dll is in the cwd and tries to dynamically 
look up entry points in it. Failing to find them, it executes line 484 
with a NULL alcOpenDeviceFxn and crashes jumping to PC 0x0. Here is the 
stack trace from Visual Studio:

	OpenAL32.dll!FindDllWithMatchingSpecifier(char 
*dllSearchPattern=0x02c9656c, char * specifier=0x0007f7b4, bool 
partialName=false, char * actualName=0x0007f780)  Line 1025	C++

  	OpenAL32.dll!alcGetString(ALCdevice_struct * device=0x00000000, int 
param=4100)  Line 1865 + 0x19	C++

  	OpenAL32.dll!alcOpenDevice(const char * deviceName=0x00000000)  Line 
1630 + 0x11	C++

I don't know what the correct fix is but at least there should be a test 
against alcOpenDeviceFxn being null at this point. Is this sufficient to 
pinpoint the bug and what the fix should be?

As a workaround we've renamed joal.dll to joal_native.dll but this could 
happen with any other DLL ending in "oal.dll" so it should definitely be 
fixed.

Thanks,

-Ken