PI50494: INCORRECT OUTPUT WHEN READING FROM A FILE

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When compiling with OPT, the exe doesn't produce the correct
  output when reading from a file. The source snippet that shows
  the incorrect output is as follows:
  
  The error is in the following coding marked with ">>"
  --------------------------------------------------------------
  while(ll)
    {
      ll = maxbuflen;
      clear(InBuffer);
      ll = fread(InBuffer, 1, ll, fpFileD431);
      if(!ll)               // EOF
        {
          break;
        }
      InCnt++;
      printf("InCnt=<%d>, ll=<%d>, InBuffer=<%.10s>\n",
                                   InCnt, ll, InBuffer);
      fflush(NULL);
  >>  printf("InCnt=<%d>\n", InCnt);   (add. line in old compiler)
  >>  if(InCnt > 6)
  >>    {
  >>      printf("InCnt > 6: InBuffer=<%10.10s>\n", InBuffer
          fflush(NULL);
          if(ll < 16)
          {
            InBuffer[ll] = '\0';  // convert to string
            printf("ll < 16: InBuffer=<%10.10s>\n", InBuffer);
            fflush(NULL);
            TmpFooter = atoi(InBuffer) - 6; // remember BK NLB
  Footer
            rc = string2decimal(&nFooter,sizeof(nFooter),
                                InBuffer, strlen(InBuffer));
            nFooter -= 7;  // correcting, 5*header,1 headline,1
  Footer
            footer++;      // because correction (empty file)
  #DN001
            break;
          }
        }
    } // while(ll)
  -----------------------------------------------------------
  
  ===== ACTUAL OUTPUT:
  $ ./a.out
  Start ReadD431
  ICBTGTST: InCnt=1
  ICBTGTST: InCnt=2
  ICBTGTST: InCnt=3
  ICBTGTST: InCnt=4
  ICBTGTST: InCnt=5
  ICBTGTST: InCnt=6
  ICBTGTST: InCnt=7
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=7
  ICBTGTST: InCnt=8
  ICBTGTST: InCnt=9
  ICBTGTST: InCnt=10
  ICBTGTST: InCnt=11
  ICBTGTST: InCnt=12
  ICBTGTST: InCnt=13
  ICBTGTST: InCnt=14
  ICBTGTST: InCnt=15
  ICBTGTST: InCnt=16
  ICBTGTST: InCnt=17
  ICBTGTST: InCnt=18
  ICBTGTST: InCnt=19
  ## ICBTGTST: Kein Footer es erfolgt abbruch.
  Ende  ReadD431!
  $
  
  
  ===== EXPECTED OUTPUT:
  $ ./a.out
  Start ReadD431
  ICBTGTST: InCnt=1
  ICBTGTST: InCnt=2
  ICBTGTST: InCnt=3
  ICBTGTST: InCnt=4
  ICBTGTST: InCnt=5
  ICBTGTST: InCnt=6
  ICBTGTST: InCnt=7
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=7
  ICBTGTST: InCnt=8
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=8
  ICBTGTST: InCnt=9
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=9
  ICBTGTST: InCnt=10
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=10
  ICBTGTST: InCnt=11
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=11
  ICBTGTST: InCnt=12
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=12
  ICBTGTST: InCnt=13
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=13
  ICBTGTST: InCnt=14
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=14
  ICBTGTST: InCnt=15
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=15
  ICBTGTST: InCnt=16
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=16
  ICBTGTST: InCnt=17
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=17
  ICBTGTST: InCnt=18
  ICBTGTST: Muss wenn InCnt>6 immer kommen.=18
  Ende  ReadD431!
  $
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: zOS XLC users with source compiled at OPT    *
  *                 with opportunities for branch folding        *
  ****************************************************************
  * PROBLEM DESCRIPTION: After a branch was folded and the       *
  *                      condition to the label removed the      *
  *                      label indicator bit was not updated to  *
  *                      reflect it being unguarded, therefore   *
  *                      setting up another optimization down    *
  *                      the stream to make an incorrect         *
  *                      assumption and transform the code       *
  *                      incorrectly.                            *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  

Problem conclusion

• Apply provided service.
  

Temporary fix

Comments

APAR Information

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

  PI36266

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

Modules/Macros

•    CCNETBY
  

Fix information

• Fixed component name

  C/C++ FOR MVS

• Fixed component ID

  56551210A

Applicable component levels

• R791 PSY UI32071

     UP15/11/21 P F511

Fix is available

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