Q26898: CASE Statement Never Executed When Tracing with F8 Key in QB

Article: Q26898
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | buglist4.00 buglist4.00b fixlist4.50 | mspl13_basic
Last Modified: 8-FEB-1990

When a CASE statement is selected inside the QuickBASIC Version 4.00
or 4.00b editor as a breakpoint, that CASE is never executed when
tracing through the program using the F8 key.

Microsoft has confirmed this to be a problem in QuickBASIC Versions
4.00 and 4.00b and the QB.EXE editor provided with Microsoft BASIC
Compiler Versions 6.00 or 6.00b for MS-DOS and MS OS/2 (buglist6.00,
buglist6.00b). This problem was corrected in QuickBASIC Version 4.50
and in the QBX.EXE environment of Microsoft BASIC Professional
Development System (PDS) Version 7.00 (fixlist7.00). QuickBASIC 4.50
and BASIC PDS 7.00 do not allow CASE statements to become breakpoints,
and will give an appropriate error message when an attempt is made to
make a CASE statement a breakpoint.

In the following example, the PRINT "a$= "; a$ statement is never
executed when the line CASE "a" is set as a breakpoint.

Results of testing with previous versions indicate that Version 3.00
will allow the CASE statement to execute when it is set as a
breakpoint.

The following code example demonstrates the problem:

CLS
a$ = "a"
SELECT CASE a$
        CASE "a"                  'Set as breakpoint and PRINT "a$..." is
             PRINT "a$= "; a$     'never executed when step through using
        CASE ELSE                 'F8.
END SELECT
PRINT "done"                      'always executed
END

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