Dlls/winmm/lolvldrv.c has a function (MMDRV_Message) shared by the Win16 and the Win32 implementation of mmsystem. Since it is shared by both mmsystem.dll and winmm.dll, all Win16 APIs used in the shared functions will be imported by the Win32 implementation (winmm.dll) also. On ReactOS no such APIs exist so the library will not load.
I see two immediate solutions:
1) Check with a preprocessor variable and not compile the Win16 part of the shared Win16/Win32 functions when --disable-win16 is specified.
2) Duplicate the shared code in a Win32 specific file and Win16 specific file.
How should it be handled?
Casper Hornstrup