Q68111: No Mouse with GRDEMO.EXE Sample Program May Cause M6111

Article: Q68111
Product(s): See article
Version(s): 2.50 2.51
Operating System(s): MS-DOS
Keyword(s): ENDUSER | buglist2.50 s_quickasm | mspl13_c
Last Modified: 17-JAN-1991

The Microsoft QuickC versions 2.50 and 2.51 compiler includes a sample
program called GRDEMO.EXE that is created using GRDEMO.MAK. The module
MOUSE.C incorrectly returns from the function MouseInit() when no
mouse is found. It will return without cleaning up the stack, which
may cause the following error:

   run-time error M6111: MATH
   floating-point error: stack underflow

To work around this problem, make the following programming changes in
MOUSE.C, and rebuild the program:

1. Change line 74 from

      ret

   to the following:

      jmp    nomouse

2. Add the label "nomouse" just prior to the end of the inline
   assembly code:

   ...
      mov   mi.cBtn, bx      ; Save...
   nomouse:
   }

Microsoft has confirmed this to be a problem in QuickC versions 2.50
and 2.51. We are researching this problem and will post new
information here as it becomes available.