BUG: xlCoerce() Can Cause GP Fault in EXCEL.EXE

ID: Q98379

The information in this article applies to:

Microsoft Excel Software Development Kit

SYMPTOMS

Calling xlCoerce() from a dynamic-link library (DLL) function causes a general protection (GP) fault in the following circumstances:

The source XLOPER is xltypeRef or xltypeSRef

The destination XLOPER is xltypeMulti

The source reference contains one or more uncalculated cells

Consider the following code fragment:


   xlDest.xltype = xltypeInt;
   xlDest.val.w  = xltypeMulti;

   Excel4(
      xlCoerce,
      &xlResult,
      2,
      (LPXLOPER) &xlSource,
      (LPXLOPER) &xlDest
   );

This code causes a GP fault if xlSource is type xltypeSRef or xltypeRef, and xlSource references uncalculated cells.

CAUSE

This is caused by a problem in Excel 4.0.

RESOLUTION

The workaround for this problem is to use xlCoerce() to individually look up cells in xltypeSRef or xltypeRef. The Software/Data Library contains a modified version of the Framework library that demonstrates this method. For more information, query on the following keywords:

p_xlsdk and softlib and framewrk

STATUS

Microsoft has confirmed this to be a problem in Microsoft Excel version 4.0. We are researching this problem and will post new information here as it becomes available.

MORE INFORMATION

This problem can be reproduced using the FuncSum() function provided by the Excel SDK GENERIC sample:

Load GENERIC.XLL.

Enter these formulae on a worksheet:
1. A1: =RAND()
2. A2: =A1
3. A3: =FuncSum(A1:A2)
4. A1: =2

Changing cell A1 from 1 to 2 causes FuncSum() to recalculate. Cell A2 is still uncalculated at that point, and Microsoft Excel will crash. This behavior results from the problem with the xlCoerce() function.

Additional query words: crash gp-fault

Keywords :
Version : :
Platform :
Issue type :