Proposals / #1546

Mac GetUserDefaultLangID: int32_t __cdecl (void) Mac region code shim

checked · by KierTaylor · submitted 2026-11-08

It reads no register or stack args. It loads the 'itlc' resource (0x0030b618) and returns its +0xc region word, sign-extended (EDI; 0 if missing), via MOV EAX,EDI at 0x0002b16e. Callers use it as a table index: LOCALE_BuildLangIdFromMac 0x0002b06f moves EAX to ECX and compares it with 0x6a before the LANGID table lookup. On Mac this returns the raw Mac region code, not a Win32 LANGID, so it is typed int32_t.

Changes 1, applied together

1. Set prototype mac 0x0002b126

   signatureundefined GetUserDefaultLangID(void)→int32_t GetUserDefaultLangID(void)
   conventionunknown→__cdecl