longout record: detect OUT link change using special function AFTER put, better documentation

modules/database/src/std/rec/longoutRecord.c

@@ -217,9 +217,9 @@ static long special(DBADDR *paddr, int after)
             return(0);
         }
 
-        /* Detect an output link re-direction (change)*/
+        /* Detect an output link re-direction (change) */
         if (dbGetFieldIndex(paddr) == longoutRecordOUT) {
-            if (!after)
+            if (after)
                 prec->outpvt = OUT_LINK_CHANGED;
             return(0);
         }
@@ -492,4 +492,4 @@ static long conditional_write(longoutRecord *prec)
     prec->pval = prec->val;
     prec->outpvt = OUT_LINK_UNCHANGED; /* reset status of OUT link */
     return status;
-}
+}

modules/database/src/std/rec/longoutRecord.dbd.pod

@@ -95,8 +95,7 @@ written to. It's a menu field that has six choices:
 C<Every Time> -- write output every time record is processed. (DEFAULT)
 
 =item *
-C<On Change> -- write output every time VAL changes, i.e., every time the
-result of the expression changes.
+C<On Change> -- write output every time VAL changes.
 
 =item *
 C<When Zero> -- when record is processed, write output if VAL is zero.
@@ -117,8 +116,10 @@ VAL is non-zero and last value was zero.
 
 =head4 Changes in OUT field when OOPT = On Change
 
-The OOCH field determines if a change in OUT field should cause a write operation
-even when the value is the same and OOPT = On Change. By default, OOCH is set to YES.
+If OOCH is C<YES> (its default value) and the OOPT field is C<On Change>,
+the record will write to the device support the first time the record gets
+processed after its OUT link is modified, even when the output value has
+not actually changed.
 
 =cut