Merge pull request #280 from vargajb/master

Error handling after increasing the array index

Author: tanto259

COBOL Programming Course #3 - Advanced Topics/Challenges/Debugging/cbl/CBL0106C.cbl

@@ -44,9 +44,10 @@
       *
        WORKING-STORAGE SECTION.
        01  Filler.
-           05 LASTREC          PIC X VALUE SPACE.
+           05 LASTREC          PIC X          VALUE SPACE.
            05 DISP-SUB1        PIC 9999.
            05 SUB1             PIC 99.
+           05 OVERLIMIT-MAX    PIC S9(4) COMP VALUE 20.
 
          01 OVERLIMIT.
            03 FILLER OCCURS 20 TIMES.
@@ -136,7 +137,7 @@
            WRITE PRINT-REC FROM HEADER-3.
            WRITE PRINT-REC FROM HEADER-4.
            MOVE SPACES TO PRINT-REC.
-           MOVE 1 TO SUB1.
+           MOVE 0 TO SUB1.
       *
        READ-NEXT-RECORD.
            PERFORM READ-RECORD
@@ -162,11 +163,19 @@
       *
        IS-OVERLIMIT.
            IF ACCT-LIMIT < ACCT-BALANCE THEN
+               ADD 1 TO SUB1
+      * Check if there is enough space in the array, in case the input 
+      * file changes again. A handled error is easier to find and fix 
+      * than a buffer overwrite error.
+               IF SUB1 > OVERLIMIT-MAX THEN
+                   DISPLAY 'OVERFLOW TABLE OVERLIMIT'
+                   MOVE 1000 TO RETURN-CODE
+                   STOP RUN
+               END-IF
                MOVE ACCT-LIMIT TO OL-ACCT-LIMIT(SUB1)
                MOVE ACCT-BALANCE TO OL-ACCT-BALANCE(SUB1)
                MOVE LAST-NAME TO OL-LASTNAME(SUB1)
                MOVE FIRST-NAME TO OL-FIRSTNAME(SUB1)
-               ADD 1 TO SUB1
             END-IF.
       *
        IS-STATE-VIRGINIA.
@@ -175,7 +184,7 @@
            END-IF.
       *
        WRITE-OVERLIMIT.
-           IF SUB1 = 1 THEN
+           IF SUB1 = 0 THEN
                MOVE OVERLIMIT-STATUS TO PRINT-REC
                WRITE PRINT-REC
            ELSE