select.result, select.test:

  Added a test case for bug #11745.
sql_select.cc:
  Fixed bug # 11745.
  Added support of where clause for queries with FROM DUAL.
sql_yacc.yy:
  Fixed bug # 11745.
  Added optional where clause for queries with FROM DUAL.

mysql-test/r/select.result

@@ -2582,3 +2582,19 @@ a
 254
 255
 drop table t2;
+CREATE TABLE t1 (a int, b int, c int);
+INSERT INTO t1
+SELECT 50, 3, 3 FROM DUAL
+WHERE NOT EXISTS
+(SELECT * FROM t1 WHERE a = 50 AND b = 3);
+SELECT * FROM t1;
+a	b	c
+50	3	3
+INSERT INTO t1
+SELECT 50, 3, 3 FROM DUAL
+WHERE NOT EXISTS
+(SELECT * FROM t1 WHERE a = 50 AND b = 3);
+SELECT * FROM t1;
+a	b	c
+50	3	3
+DROP TABLE t1;

mysql-test/t/select.test

@@ -2138,3 +2138,21 @@ insert into t2 values (0), (254), (255);
 explain select * from t2 where a > -1;
 select * from t2 where a > -1;
 drop table t2;
+
+#
+# Bug #11745: SELECT ... FROM DUAL with WHERE condition
+#
+
+CREATE TABLE t1 (a int, b int, c int);
+INSERT INTO t1
+  SELECT 50, 3, 3 FROM DUAL
+    WHERE NOT EXISTS
+      (SELECT * FROM t1 WHERE a = 50 AND b = 3);
+SELECT * FROM t1;
+INSERT INTO t1
+  SELECT 50, 3, 3 FROM DUAL
+    WHERE NOT EXISTS
+      (SELECT * FROM t1 WHERE a = 50 AND b = 3);
+SELECT * FROM t1;
+
+DROP TABLE t1;

sql/sql_select.cc

@@ -1072,7 +1072,7 @@ JOIN::exec()
     else
     {
       result->send_fields(fields_list,1);
-      if (!having || having->val_int())
+      if (cond_value != Item::COND_FALSE && (!having || having->val_int()))
       {
 	if (do_send_rows && (procedure ? (procedure->send_row(fields_list) ||
                                           procedure->end_of_records())

sql/sql_yacc.yy

@@ -2459,7 +2459,7 @@ select_into:
 select_from:
 	  FROM join_table_list where_clause group_clause having_clause
 	       opt_order_clause opt_limit_clause procedure_clause
-        | FROM DUAL_SYM opt_limit_clause
+        | FROM DUAL_SYM where_clause opt_limit_clause
           /* oracle compatibility: oracle always requires FROM clause,
              and DUAL is system table without fields.
              Is "SELECT 1 FROM DUAL" any better than "SELECT 1" ?