PH28398: INSPECT SHOULD NOT MODIFY AN INSPECTED ITEM (CHAPTER 17 OF THE V6+ MIGRATION GUIDE FOR INSPECT ... TALLYING)

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Given this code:
  
          WORKING-STORAGE SECTION.
  
          01  TEST-DATA.
              02  NUM-DISP PIC  S9(4).
  
          PROCEDURE DIVISION.
          BEGIN.
  
              MOVE 0 To TALLY
              MOVE SPACES TO TEST-DATA
              INSPECT NUM-DISP TALLYING TALLY FOR ALL '0'
              IF TALLY > 0 THEN
                DISPLAY 'This is COBOL V4 or earlier'
              ELSE
                DISPLAY 'This is COBOL V6+'
              END-IF
              DISPLAY 'TALLY = <' TALLY '>'.
              DISPLAY 'TEST DATA = <' TEST-DATA '>'.
              GOBACK.
  
  Chapter 17 of the COBOL V5+ Migration Guide documents that
  "COBOL V5 and later versions will not unexpectedly modify the
  inspected data item."
  
  However, the COBOL Runtime has an error in internal logic such
  that when the inspected item is a signed zoned-decimal data
  item, such as NUM-DISP PIC S9(9), then TALLY in the above
  example will not equal zero as it should. When spaces are moved
  to TEST-DATA, its value is x'404040404040404040'. The runtime
  error causes the sign nibble to become x'4040404040404040F0',
  which causes the INSPECT to find 1 zero.
  
  If the inspected item is unsigned (without 'S'), the error does
  not happen.
  

Local fix

• Add a NUMERIC class test before the INSPECT, avoid moving
  spaces or alphanumeric data into the inspected item, or move
  zeroes into the inspected item.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Enterprise COBOL V5 and later       *
  *                 releases running programs which use          *
  *                 the INSPECT ... TALLYING statement.          *
  ****************************************************************
  * PROBLEM DESCRIPTION: The INSPECT ... TALLYING statement      *
  *                      incorrectly counts the occurrence of    *
  *                      a specific character.                   *
  ****************************************************************
  * RECOMMENDATION: Install the provided PTF.                    *
  ****************************************************************
  When an item to be inspected is signed numeric display
  (zoned-decimal) that is initialized with a non-numerical value
  such as spaces, COBOL Runtime inadvertently processes the sign
  nibble of the item as if it contains x'F'.
  
  For example,
  ...
  WORKING-STORAGE SECTION.
  01  TALLY-IT                     PIC 9 VALUE 0.
  01  TEST-DATA.
      02  NUM-DISP PIC S9(9).
  ...
  PROCEDURE DIVISION.
      MOVE SPACES TO TEST-DATA.
      INSPECT NUM-DISP TALLYING TALLY-IT FOR ALL '0'.
      DISPLAY 'TALLY-IT = ' TALLY-IT.
      GOBACK.
  
  This program outputs:
  TALLY-IT = 1
  
  COB0501T/K COB0502T/K COB0601T/K COB0602T/K COB0603T/K
  

Problem conclusion

• The INSPECT processing in the COBOL Runtime has been corrected.
  With the correction, the above example outputs:
  TALLY-IT = 0
  
  For more details, refer to the 'INSPECT...TALLYING behavior'
  in 'Enterprise COBOL for z/OS Migration guide'. Below is quoted
  from the Migration Guide:
  
  "INSPECT...TALLYING behavior
  ...
  For INSPECT...TALLYING, previous versions of the compiler
  insert zone nibbles in a signed numeric display inspected
  item before performing the INSPECT. This will, for example,
  change SPACES to ZEROS. COBOL V5 and later releases no longer
  do this zone normalization."
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Modules/Macros

• IGZCEV4  IGZLLIBV IGZXAPI  IGZXCDA  IGZXD24  IGZXDMR  IGZXLPIO
  IGZXLPKA IGZXLPKB IGZXLPKC IGZXLPKD IGZXLPKE IGZXLPKF IGZXLPKG
  IGZXPK2
  

Fix information

• Fixed component name

  LE ENT COBOL LI

• Fixed component ID

  568819812

Applicable component levels

• R7A0 PSY UI71561

     UP20/09/26 P F009

• R7B0 PSY UI71562

     UP20/09/26 P F009

• R7C0 PSY UI71563

     UP20/09/26 P F009

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.