PRB: DrawText Can Cause Stack Fault

• Microsoft Windows Software Development Kit (SDK) for Windows, versions 3.1, 3.11

SYMPTOMS

In Windows versions 3.1 and 3.11, when a string that contains long, contiguous substrings of spaces is passed to DrawText, and the DT_WORDBREAK flag is specified, a stack fault may occur.

CAUSE

The DT_WORDBREAK flag specifies that DrawText break the string between words. The method used by DrawText to determine where these breaks occur involves recursion. If the stack size is small enough and the number of spaces is large enough, the recursion causes a stack fault.

RESOLUTION

There are two ways to work around this problem. One is to raise the stack size of the application. This can be done by adding a STACKSIZE statement to the application's .DEF file.

Another solution that drastically speeds up the call to DrawText is to parse the string and turn all contiguous strings of spaces into single spaces. The resulting string can then be passed to DrawText without the overhead that the original string would have demanded.