Q65831: BASIC 7.00 QBX.EXE: PAINT Statement Uses Far Heap

Article: Q65831
Product(s): See article
Version(s): 7.00
Operating System(s): MS-DOS
Keyword(s): ENDUSER | SR# S900920-17 buglist7.00 fixlist7.10 | mspl13_basic
Last Modified: 18-OCT-1990

In the QBX.EXE environment of Microsoft BASIC Professional Development
System (PDS) version 7.00, the PAINT statement allocates an area of
memory in the far heap that cannot be deallocated.

Microsoft has confirmed this to be a problem in the QBX.EXE
environment of Microsoft BASIC PDS version 7.00 for MS-DOS. This
problem was corrected in the QBX.EXE environment of Microsoft BASIC
PDS version 7.10 for MS-DOS.

The following code example demonstrates the problem. When run inside
the QBX.EXE environment of version 7.00, the values returned by the
FRE(-1) function are different. The problem does not appear in a
compiled .EXE program.

Code Example
------------

   CLS
   SCREEN 1
   CIRCLE (190, 100), 100, 1, , , .3  'Draw an ellipse
   PRINT FRE(-1)                      'Print far heap memory available
   PAINT (190, 100), 2, 1             'Fill in the ellipse
   PRINT FRE(-1)   'This FRE(-1) value is different than previous FRE(-1)