row0ins.c:

  Do not perform ON DELETE action for a FOREIGN KEY constraint if we are doing an UPDATE, not a DELETE
dict0dict.c:
  test

innobase/dict/dict0dict.c

@@ -270,7 +270,7 @@ void
 dict_table_autoinc_initialize(
 /*==========================*/
 	dict_table_t*	table,	/* in: table */
-	ib_longlong	value)	/* in: value which was assigned to a row */
+	ib_longlong	value)	/* in: next value to assign to a row */
 {
 	mutex_enter(&(table->autoinc_mutex));
 
@@ -281,8 +281,8 @@ dict_table_autoinc_initialize(
 }
 
 /************************************************************************
-Gets the next autoinc value, 0 if not yet initialized. If initialized,
-increments the counter by 1. */
+Gets the next autoinc value (== autoinc counter value), 0 if not yet
+initialized. If initialized, increments the counter by 1. */
 
 ib_longlong
 dict_table_autoinc_get(
@@ -298,8 +298,8 @@ dict_table_autoinc_get(
 
 		value = 0;
 	} else {
-		table->autoinc = table->autoinc + 1;
 		value = table->autoinc;
+		table->autoinc = table->autoinc + 1;
 	}
 	
 	mutex_exit(&(table->autoinc_mutex));
@@ -334,20 +334,43 @@ dict_table_autoinc_read(
 }
 
 /************************************************************************
-Updates the autoinc counter if the value supplied is bigger than the
+Peeks the autoinc counter value, 0 if not yet initialized. Does not
+increment the counter. The read not protected by any mutex! */
+
+ib_longlong
+dict_table_autoinc_peek(
+/*====================*/
+				/* out: value of the counter */
+	dict_table_t*	table)	/* in: table */
+{
+	ib_longlong	value;
+
+	if (!table->autoinc_inited) {
+
+		value = 0;
+	} else {
+		value = table->autoinc;
+	}
+
+	return(value);
+}
+
+/************************************************************************
+Updates the autoinc counter if the value supplied is equal or bigger than the
 current value. If not inited, does nothing. */
 
 void
 dict_table_autoinc_update(
 /*======================*/
+
 	dict_table_t*	table,	/* in: table */
 	ib_longlong	value)	/* in: value which was assigned to a row */
 {
 	mutex_enter(&(table->autoinc_mutex));
 
 	if (table->autoinc_inited) {
-		if (value > table->autoinc) {
-			table->autoinc = value;
+		if (value >= table->autoinc) {
+			table->autoinc = value + 1;
 		}
 	}	
 

innobase/row/row0ins.c

@@ -389,9 +389,21 @@ row_ins_foreign_delete_or_set_null(
 	char		err_buf[1000];
 	
 	ut_a(thr && foreign && pcur && mtr);
+	ut_a(que_node_get_type(node) == QUE_NODE_UPDATE);
 
 	node = thr->run_node;
 
+	if (!node->is_delete) {
+	        /* According to SQL-92 an UPDATE with respect to FOREIGN
+	        KEY constraints is not semantically equivalent to a
+                DELETE + INSERT. Therefore we do not perform any action
+	        here and consequently the child rows would be left
+	        orphaned if we would let the UPDATE happen. Thus we return
+		an error. */
+
+	        return(DB_ROW_IS_REFERENCED);
+	}
+
 	if (node->cascade_node == NULL) {
 		/* Extend our query graph by creating a child to current
 		update node. The child is used in the cascade or set null