#12 BWBasic 3.2 freezes after entering run#

[Oliver]

I wrote a small BASIC listing and accidentally pressed the "#" key before pressing the return key after i entered run. The result was, that the BWBASIC interpreter freezes when run# is entered instead of run.

The "#" key is next to the "RETURN" key on a German keyboard layout. Therefore, it is not difficult to accidentally press it when trying to press RETURN.

[AF5NE]

Thanks for finding this bug. Sorry for the delay in responding - I am not often online. If you are comfortable updating the source code with diff/patch, the attached "patch-20230417.txt" should fix this bug and all the other bugs I know about.

If you are not comfortable with diff/patch, then open "bwb_cmd.c" with a text editor and goto to around line 1555, which should look like this:

   if (line_read_expression (L, X) == FALSE)        /* bwb_run_filename_or_linenumber */
   {
     WARN_SYNTAX_ERROR;
     return L;
   }

Update that section to this:

  if (line_read_expression (L, X) == FALSE)        /* bwb_run_filename_or_linenumber */
  {
    WARN_SYNTAX_ERROR;
/*
Bug #12 BWBasic 3.2 freezes after entering run#
*/
L = NULL;
    return L;
  }

After recompiling the following test confirms that bug is fixed.

bwBASIC: LIST
  100 REM RUN
  110 PRINT "TEST RUN # 200"
  120 RUN # 200
  130 PRINT "FAILED @ 130"
  140 END
  200 PRINT "PASSED @ 200"
  999 END
bwBASIC: RUN
TEST RUN # 200
PASSED @ 200
bwBASIC: RUN #200
PASSED @ 200
bwBASIC: RUN # 200
PASSED @ 200
bwBASIC: RUN #
ERROR: Syntax error
bwBASIC: RUN#
ERROR: Syntax error
bwBASIC: RUN 200
PASSED @ 200

[Oliver]

Thank you a lot for fixing that bug. Your fix worked. But i found another bug that is related to this bug.

BWBasic freezes when trying to run code starting with a line number that is not in the code listing.
I used your code listing example above and entered:

  run 150

And after pressing the return key, BWBasic freezes. See the screenshot below.
The same applies for variants like this one:

  run # 150

or

  run #150

I added your fix manually. I didn't use the diff patch because I didn't have the appropriate diff software installed in FreeDOS 1.3.

[Oliver]

As an additional information to my last comment:

I was curious how GW-BASIC reacts when entering a line number that doesn't exist.
When trying to do so, it prints the line:

  Undefined line number
  OK

And returns to the GW-BASIC interpreter.
See screenshot as an example:

[Oliver]

One more information.

I found out that it is possible to switch back to the interpreter by pressing
CTRL + C when a none existing line number was given to run the basic code.

The problem with this is, BWBasic returns to the interpreter only, when only a number like

run 150

was given and the keys CTRL+C was pressed

If i enter a number with a # character

run # 150

and then press the CTRL+C key, then BWBasic exists or crashes to DOS prompt.

But from there, the memory seems to be rather corrupted, because additional DOS commands, for example

mem

do throw an exception.
Thus BWBasic doesn't exit in a clean way at this point.

See the screenshots for example.

[AF5NE]

Glad the initial bug is fixed. The attached "patch-20230419.txt" should fix the second bug you reported above.

[AF5NE]

After recompiling the following test should confirm the second bug is fixed.

bwBASIC: REM TEST 'RUN' COMMAND
bwBASIC: 
bwBASIC: 
bwBASIC: LIST
  100 PRINT "HELLO"

bwBASIC: SAVE "GOOD.BAS"
bwBASIC: 
bwBASIC: 
bwBASIC: REM THESE SHOULD DISPLAY "HELLO"
bwBASIC: 
bwBASIC: 
bwBASIC: RUN
HELLO
bwBASIC: RUN 100
HELLO
bwBASIC: RUN#100
HELLO
bwBASIC: RUN "GOOD.BAS"
HELLO
bwBASIC: 
bwBASIC: 
bwBASIC: REM THESE SHOULD DISPLAY AN ERROR MESSAGE
bwBASIC: 
bwBASIC: 
bwBASIC: RUN 1

ERROR: Undefined line
bwBASIC: RUN 999

ERROR: Undefined line
bwBASIC: RUN#

ERROR: Syntax error
bwBASIC: RUN#1

ERROR: Undefined line
bwBASIC: RUN#999

ERROR: Undefined line
bwBASIC: RUN ""

ERROR: Bad file name
bwBASIC: RUN "BOGUS.BAS" 

ERROR: Bad file name
bwBASIC: 
bwBASIC: 
bwBASIC: REM CREATE A FILE CONTAINING ERRORS
bwBASIC: 
bwBASIC: 
bwBASIC: NEW
bwBASIC: OPEN "BAD.BAS" FOR OUTPUT AS #1
bwBASIC: PRINT #1, "100 NO SUCH COMMAND"
bwBASIC: CLOSE #1
bwBASIC: 
bwBASIC: 
bwBASIC: REM THIS SHOULD DISPLAY AN ERROR MESSAGE
bwBASIC: 
bwBASIC: 
bwBASIC: RUN "BAD.BAS" 
ILLEGAL COMMAND AFTER LINE NUMBER: 100 NO SUCH COMMAND

ERROR in line 100: Illegal direct

STACK TRACE:
100:NO SUCH COMMAND
bwBASIC: 
bwBASIC: 
bwBASIC: REM THIS SHOULD *NOT* DISPLAY AN ERROR MESSAGE
bwBASIC: 
bwBASIC: 
bwBASIC: NEW
bwBASIC: RUN
bwBASIC: 
bwBASIC: 
bwBASIC: REM CLEANUP
bwBASIC: 
bwBASIC: 
bwBASIC: KILL "GOOD.BAS"
bwBASIC: KILL "BAD.BAS"

[Oliver]

Thank you very much.
I can report that your second patch fixed the second bug.
I did your test and everything worked like it should.
Great work!