Q37483: CHAIN "RETURN Without GOSUB" When Using ON ERROR GOTO & No /O

Article: Q37483
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | B_BasicCom | mspl13_basic
Last Modified: 12-JAN-1990

When chaining from a program that does not trap errors (ON ERROR GOTO)
to a program that does, a "RETURN without GOSUB" error message can
appear. This occurs only when the programs are compiled requiring the
run-time library BRUN4x.EXE.

Because the run-time system is initialized in the first program, you
need to compile both programs with BC /E to support error trapping.

Another way to avoid this problem is to compile both programs with BC
/O to make them stand alone. With this process, the chaining program
does not require compiling with /E.

This information applies to Microsoft QuickBASIC Versions 4.00, 4.00b,
and 4.50 and to Microsoft BASIC Compiler Versions 6.00 and 6.00b for
MS-DOS and MS OS/2. The code below does not generate the error
described above with Microsoft BASIC PDS Version 7.00.

The programs below, when compiled without /O, will give the "RETURN
without GOSUB" run-time error message in the second program.

Code Examples
-------------

The first program is as follows:

' TEST.BAS
      CHAIN "test1"
      END

The second program is as follows:

' TEST1.BAS
      ON ERROR GOTO 0
      K% = 1
      ON K% GOSUB handle
      END
handle:
      A$ = INKEY$: IF A$ = "" THEN GOTO handler
      RETURN

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