Q67363: In QBX 7.10, F8 Step then Editing Active Statement Can Fail

Article: Q67363
Product(s): See article
Version(s): 7.10
Operating System(s): MS-DOS
Keyword(s): ENDUSER | buglist7.10 | mspl13_basic
Last Modified: 5-DEC-1990

When you single step (F8) through a program in the QBX.EXE version
7.10 environment, editing the active (highlighted) statement can give
unexpected results under certain circumstances. For example, if you
attempt to split the active line in two by pressing the ENTER key, the
next line may duplicate the current line. Sometimes the first line
splits correctly but the next line becomes an altered version of the
first line. Note that pressing "ALT+BACKSPACE" will usually undo the
editing problem.

Microsoft has confirmed this to be a problem with the QuickBASIC
extended environment (QBX.EXE) that comes with Microsoft BASIC
Professional Development System (PDS) version 7.10 for MS-DOS. We are
researching this problem and will post new information here as it
becomes available.

This problem can occur on any statement where a variable is first
declared, including the following statements: COMMON SHARED, DIM
SHARED, REDIM, FOR, WHILE, DO...LOOP, or IF. When creating the problem
with FOR, WHILE, DO...LOOP, or IF statements, you must actually try
and divide the BASIC reserved word (for example, put the cursor in the
middle of WHILE and press ENTER).

To reproduce the problem, perform the following steps:

1. Add the line below to the beginning of an empty program window:

      COMMON SHARED A, B

2. Make the line the current executing line by single stepping with
   the F8 key until that line is highlighted.

3. Now put the cursor anywhere before the "B" (for example, put the
   cursor on the "A") and press ENTER.

4. A dialog box will appear saying "You will have to restart your
   program after this edit. Proceed anyway?" Press ENTER.

5. Your source code will now resemble the following:

      COMMON SHARED A
      COMMON SHARED A, B

To reproduce the problem with an assignment statement, enter the
single BASIC line of code "x = a + b + c" and follow the steps above.
When the line is highlighted, place the cursor on the variable "a" and
press ENTER. This will not duplicate the current line but will cause
the "+" to be deleted between a and b.

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