Illegal RESUME NEXT Hangs QBX After ON LOCAL ERROR RESUME NEXT

Retired KB Content Disclaimer

This article was previously published under Q63811

SYMPTOMS

QBX.EXE hangs if an illegal RESUME NEXT statement is encountered in an IF statement inside a SUB where the statement ON LOCAL ERROR RESUME NEXT is active. This problem does not occur in a compiled and linked .EXE program.

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STATUS

Microsoft has confirmed this to be a bug in QBX.EXE in Microsoft Basic Professional Development System (PDS) versions 7.00 and 7.10 for MS-DOS. We are researching this problem and will post new information here as it becomes available.

The problem can be worked around by knowing and not programming illegal "RESUME without error" conditions.

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MORE INFORMATION

Instead of hanging the program below, the QBX environment should return an Error 20 ("RESUME without error"), which means that there is no active error-handling routine from which to RESUME. Error 20 should then have been automatically handled by the ON LOCAL ERROR RESUME NEXT statement (which does a valid RESUME NEXT).

A RESUME NEXT statement by itself is only valid when it is within an error-handling routine that was an object of an ON [LOCAL] ERROR GOTO <linelabel> statement. When the program below is compiled and linked into an EXE, the .EXE does not hang, and it correctly returns and handles error 20.

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Code Example

The following code example hangs QBX.EXE on the indicated line. Note that this program shows illegal usage of the second RESUME NEXT, which should have produced error 20. When run as an .EXE program, this code successfully returns error 20 and handles the error correctly with the local error handler:

CALL test
SUB test
  ON LOCAL ERROR RESUME NEXT
  ERROR 1
  ' The following RESUME NEXT is a programming error:
  IF ERR = 1 THEN RESUME NEXT   '*** This line hangs in QBX.EXE
  ' The above statement correctly causes error 20 ("RESUME without
  ' error") in a .EXE program, and ERR now returns 20 and prints as
  ' follows:
  PRINT "This is next line after programming error 20, and ERR= "; ERR
  PRINT "Now ending subprogram"
END SUB

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KB63811

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Retired KB Content Disclaimer

This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.

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