There is a bug in the function executor. The backend crashes while trying to

scrappy · scrappy · commit 906651f66366 · 1996-09-16T05:36:38.000Z
execute an sql function containing an utility command (create, notify, ...).
The bug is part in the planner, which returns a number of plans different
than the number of commands if there are utility commands in the query, and
in part in the function executor which assumes that all commands are normal
query commands and causes a SIGSEGV trying to execute commands without plan.

Submitted by: Massimo Dal Zotto &lt;dz@cs.unitn.it&gt;
diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/executor/functions.c,v 1.1.1.1 1996/07/09 06:21:25 scrappy Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/executor/functions.c,v 1.2 1996/09/16 05:36:15 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -160,6 +160,14 @@ init_execution_state(FunctionCachePtr fcache,
 static TupleDesc
 postquel_start(execution_state *es)
 {
+#ifdef FUNC_UTIL_PATCH
+    /*
+     * Do nothing for utility commands. (create, destroy...)  DZ - 30-8-1996
+     */
+    if (es->qd->operation == CMD_UTILITY) {
+	return (TupleDesc) NULL;
+    }
+#endif
     return ExecutorStart(es->qd, es->estate);
 }
 
@@ -168,6 +176,17 @@ postquel_getnext(execution_state *es)
 {
     int feature;
     
+#ifdef FUNC_UTIL_PATCH
+    if (es->qd->operation == CMD_UTILITY) {
+	/*
+	 * Process an utility command. (create, destroy...)  DZ - 30-8-1996
+	 */
+	ProcessUtility(es->qd->parsetree->utilityStmt, es->qd->dest);
+	if (!LAST_POSTQUEL_COMMAND(es)) CommandCounterIncrement();
+	return (TupleTableSlot*) NULL;
+    }
+#endif
+
     feature = (LAST_POSTQUEL_COMMAND(es)) ? EXEC_RETONE : EXEC_RUN;
     
     return ExecutorRun(es->qd, es->estate, feature, 0);
@@ -176,6 +195,14 @@ postquel_getnext(execution_state *es)
 static void
 postquel_end(execution_state *es)
 {
+#ifdef FUNC_UTIL_PATCH
+    /*
+     * Do nothing for utility commands. (create, destroy...)  DZ - 30-8-1996
+     */
+    if (es->qd->operation == CMD_UTILITY) {
+	return;
+    }
+#endif
     ExecutorEnd(es->qd, es->estate);
 }
 
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.7 1996/09/10 06:48:52 scrappy Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.8 1996/09/16 05:36:38 scrappy Exp $
  *
  * NOTES
  *    this is the "main" module of the postgres backend and
@@ -547,6 +547,16 @@ pg_plan(char *query_string,	/* string to execute */
 	    }
 #endif
 	}
+#ifdef FUNC_UTIL_PATCH
+	/*
+	 * If the command is an utility append a null plan. This is
+	 * needed to keep the plan_list aligned with the querytree_list
+	 * or the function executor will crash.  DZ - 30-8-1996
+	 */
+	else {
+	    plan_list = lappend(plan_list, NULL);
+	}
+#endif
     }
     
     if (queryListP)
@@ -601,6 +611,14 @@ pg_eval_dest(char *query_string, /* string to execute */
     for (i=0;i<querytree_list->len;i++) {
 	querytree = querytree_list->qtrees[i];
 	
+#ifdef FUNC_UTIL_PATCH
+	/*
+	 * Advance on the plan_list in every case.  Now the plan_list
+	 * has the same length of the querytree_list.  DZ - 30-8-1996
+	 */
+	plan = (Plan *) lfirst(plan_list);
+	plan_list = lnext(plan_list);
+#endif
 	if (querytree->commandType == CMD_UTILITY) {
 	    /* ----------------
 	     *   process utility functions (create, destroy, etc..)
@@ -617,8 +635,13 @@ pg_eval_dest(char *query_string, /* string to execute */
 	    ProcessUtility(querytree->utilityStmt, dest);
 	    
 	} else {
+#ifndef FUNC_UTIL_PATCH
+	    /*
+	     * Moved before the if.  DZ - 30-8-1996
+	     */
 	    plan = (Plan *) lfirst(plan_list);
 	    plan_list = lnext(plan_list);
+#endif
 	    
 #ifdef INDEXSCAN_PATCH
 	    /*
@@ -1246,7 +1269,7 @@ PostgresMain(int argc, char *argv[])
      */
     if (IsUnderPostmaster == false) {
 	puts("\nPOSTGRES backend interactive interface");
-	puts("$Revision: 1.7 $ $Date: 1996/09/10 06:48:52 $");
+	puts("$Revision: 1.8 $ $Date: 1996/09/16 05:36:38 $");
     }
     
     /* ----------------
