Created attachment 45668 [details]
The page fault's backtrace.

Hello,

I have just compiled the latest git wine version.
wine-1.7.0-114-g73aef40

When I do
cd ~/lol/LoL_Prefix/drive_c/Riot\ Games/League\ of\ Legends && wine ./lol.launcher.exe
the LoL welcome window appears, with its prominent "Play" button.

Then when I click the "Play" button, a new large window appears with an "Account Login" form that prompts for the account and password, and almost simultaneously the Wine "Program Error" window appears, reporting a crash at dlls/winmm/waveform.c:273 (see attached file backtrace.txt).

According to traces I added, I think I have located the problem.

Except from waveform.c's WOD_Open() function:

        if(WINMM_IsMapper(info->req_device)){
            devices = g_out_mapper_devices;
            mmdevice = read_map(g_out_map, 0);
            lock = &g_devthread_lock;
            internal_index = MAPPER_INDEX;

When the user requests the WAVE_MAPPER, the code calls read_map() with device index 0 without first checking whether the number of devices is greater than 0.

Could you please have a look?

Thanks!

Best regards
Fabrice