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--- ../clipssrc0624_orig/objrtmch.c Thu Jun 15 12:04:00 2006
+++ ../clipssrc/objrtmch.c Fri Jun 23 15:17:46 2006
@@ -1,7 +1,7 @@
/*******************************************************/
/* "C" Language Integrated Production System */
/* */
- /* CLIPS Version 6.24 05/17/06 */
+ /* CLIPS Version 6.25 06/22/06 */
/* */
/* OBJECT PATTERN MATCHER MODULE */
/*******************************************************/
@@ -25,6 +25,14 @@
/* */
/* Renamed BOOLEAN macro type to intBool. */
/* */
+/* 6.25: Modified the QueueObjectMatchAction function */
+/* so that instance retract actions always occur */
+/* before instance assert and modify actions. */
+/* This prevents the pattern matching process */
+/* from attempting the evaluation of a join */
+/* expression that accesses the slots of a */
+/* retracted instance. */
+/* */
/**************************************************************/
/* =========================================
*****************************************
@@ -393,6 +401,7 @@
int slotNameID)
{
OBJECT_MATCH_ACTION *prv,*cur,*newMatch;
+ OBJECT_MATCH_ACTION *prvRetract = NULL; /* DR0873 */
prv = NULL;
cur = ObjectReteData(theEnv)->ObjectMatchActionQueue;
@@ -463,6 +472,9 @@
return;
}
+
+ if (cur->type == OBJECT_RETRACT) /* DR0873 */
+ { prvRetract = cur; } /* DR0873 */
prv = cur;
cur = cur->nxt;
}
@@ -473,11 +485,33 @@
================================================ */
newMatch = get_struct(theEnv,objectMatchAction);
newMatch->type = type;
- newMatch->nxt = cur;
+ newMatch->nxt = NULL; /* If we get here, cur should be NULL */
newMatch->slotNameIDs = (type != OBJECT_MODIFY) ? NULL :
QueueModifySlotMap(theEnv,NULL,slotNameID);
newMatch->ins = ins;
newMatch->ins->busy++;
+
+ /* DR0873 Begin */
+ /* Retract operations must be processed before assert and */
+ /* modify actions, otherwise the pattern matching process */
+ /* might attempt to access the slots of a retract instance. */
+
+ if (type == OBJECT_RETRACT)
+ {
+ if (prvRetract == NULL)
+ {
+ newMatch->nxt = ObjectReteData(theEnv)->ObjectMatchActionQueue;
+ ObjectReteData(theEnv)->ObjectMatchActionQueue = newMatch;
+ }
+ else
+ {
+ newMatch->nxt = prvRetract->nxt;
+ prvRetract->nxt = newMatch;
+ }
+ }
+ else
+ /* DR0873 End */
+
if (prv == NULL)
ObjectReteData(theEnv)->ObjectMatchActionQueue = newMatch;
else
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