[open-cobol-list] Bug in UNSTRING ... ON OVERFLOW or misunderstanding?

[Fred Mobach]

Hello,

A problem I've encountered with UNSTRING ... ON OVERFLOW, is it a bug 
that an ON OVERFLOW condition can be met more than once?

According to ISO/IEC FCD 1989:2001 the overflow condition of an unstring 
operation operates like:
16) Either of the following situations causes an overflow condition:
    a)  An UNSTRING is initiated, and the value in the data item
        referenced by identifier-7 is less than 1 or greater
        than the number of character positions described for the data
        item referenced by identifier-1.
    b)  If, during execution of an UNSTRING statement, all receiving
        areas have been acted upon, and the data
        item referenced by identifier-1 contains characters that have
        not been examined.
and the format of UNSTRING is there:
  UNSTRING identifier-1
     DELIMITED BY [ ALL ]  identifier-2      OR [ ALL ]  identifier-3 
     …
                             literal-1                   literal-2     
  INTO { identifier-4 [ DELIMITER IN identifier-5 ] [ COUNT IN 
       identifier-6 ] } ...
  [ WITH POINTER identifier-7 ]
  [ TALLYING IN identifier-8 ]
     ON OVERFLOW imperative-statement-1
     NOT ON OVERFLOW imperative-statement-2
  [ END-UNSTRING ]

While my testprogram didn't work accordingly some screen output was 
captured to show that the on overflow condition was encountered 
repeatedly and the not on overflow condition was met once :

address@hidden:~/cob> ./unstring2
on overflow, counter=+000000000002
             pointer=+000000000007
on overflow, counter=+000000000003
             pointer=+000000000016
on overflow, counter=+000000000004
             pointer=+000000000020
on overflow, counter=+000000000005
             pointer=+000000000025
on overflow, counter=+000000000006
             pointer=+000000000029
not on overflow, counter=+000000000007
                 pointer=+000000000129
index1=+000000000001 text=below      delim=
index1=+000000000002 text=mountain   delim==
index1=+000000000003 text=low        delim=,
index1=+000000000004 text=high       delim=,
index1=+000000000005 text=big        delim=,
index1=+000000000006 text=small      delim=
index1=+000000000007 text=           delim=
index1=+000000000008 text=           delim=
pointer=+000000000129
tallying=+000000000007

Tested on :
address@hidden:~/cob-idx> cat /etc/SuSE-release
openSUSE 12.1 (x86_64)
address@hidden:~/cob-idx> uname -a
Linux fred 3.1.0-1.2-desktop #1 SMP PREEMPT Thu Nov 3 14:45:45 UTC 2011 
(187dde0) x86_64 x86_64 x86_64 GNU/Linux
OpenCOBOL version used:
/* Generated by            cobc 1.1.0 */
/* Generated from          unstring2.cob */
/* Generated at            Mar 15 2012 10:19:30 CET */
/* OpenCOBOL build date    Feb 19 2012 22:24:40 */

The source unstring2.cob tested:
<<cut here>>
       >>SOURCE FORMAT IS FIXED
       identification division.
       program-id. x.
       environment division.
       data division.
       working-storage section.
       01  ws-variables.
           03  index1                pic s9(12) comp sync.
           03  string-pointer        pic s9(12) comp sync.
           03  string-counter        pic s9(12) comp sync.
           03  free-text-len-max     pic s9(12) comp sync value 128.
           03  free-text             pic x(0128).
           03  table-unstring.
               05  row-unstring                  occurs 8.
                   07  text-unstring pic x(0010).
                   07  delim-unstr   pic x(0001).
       procedure division.
       mainline section.
       p00.
           move "below mountain=low,high,big,small" to free-text
           move space to table-unstring
           move 1 to string-counter
           move 1 to string-pointer
               .
      *    Test 2 : unstring loop into one substring per cycle.
       p50.
           if string-counter < 8
      *    Absence of the and clause below let the RTS of OC hang
      *    on an input from comsole.
               and string-pointer not > free-text-len-max
               unstring free-text
                   delimited by all space or all "=" or all ","
                   into text-unstring (string-counter)
                        delimiter in delim-unstr (string-counter)
                   with pointer string-pointer
                   tallying in  string-counter
                   on overflow
                       display "on overflow, counter="
                               string-counter
                       display "             pointer="
                               string-pointer
                       go to p50
                   not on overflow
                       display "not on overflow, counter="
                               string-counter
                       display "                 pointer="
                               string-pointer
               end-unstring
           end-if
               .
           perform varying index1 from 1 by 1 until index1 > 8
               display "index1=" index1
                       " text=" text-unstring (index1)
                       " delim=" delim-unstr (index1)
           end-perform
           display "pointer=" string-pointer
           display "tallying=" string-counter
               .
       peos.
           stop run.
<<cut here>>
-- 
Fred Mobach
website : https://fred.mobach.nl
 .... In God we trust ....
 .. The rest we monitor ..