Q34913: QB.EXE "String Space Corrupt" Editing First Label in SUB

Article: Q34913
Product(s): See article
Version(s): 4.00 4.00b
Operating System(s): MS-DOS
Keyword(s): ENDUSER | B_BasicCom buglist4.00 buglist4.00b fixlist4.50 | mspl13_basic
Last Modified: 12-DEC-1989

The QuickBASIC QB.EXE editor displays the error message "String Space
Corrupt" when you perform the following steps:

1. Run QB.EXE and type the following subprogram:

   sub anyname
   label:

2. Position the cursor on the first column of the line that contains
   the label, then press the BACKSPACE key. The "String Space Corrupt"
   error message displays, control drops back to DOS, and the computer
   hangs, forcing you to restart it.

Microsoft has confirmed this to be a problem in Microsoft QuickBASIC
Versions 4.00 and 4.00b, and in the QuickBASIC editor that comes with
the Microsoft BASIC Compiler Versions 6.00 and 6.00b for MS-DOS and MS
OS/2 (buglist6.00, buglist6.00b). Microsoft has corrected this
problem in QuickBASIC Version 4.50 and in the QBX.EXE environment of
the Microsoft BASIC PDS Version 7.00 (fixlist7.00).

This problem does not occur if the subroutine has parameters, or if the
first line in the subprogram contains anything other than a label.