BUG#18198: Too flexible partition functions

mysql-test/r/partition_error.result:
  New test cases
mysql-test/t/partition_error.test:
  New test cases
sql/sql_yacc.yy:
  Verify that partition function is allowed before "fixing" it

mysql-test/r/partition_error.result

 drop table if exists t1;
 create table t1 (a int)
+partition by range (a)
+(partition p0 values less than ((select count(*) from t1)));
+ERROR HY000: This partition function is not allowed
+create table t1 (a int)
+partition by range (a)
+(partition p0 values less than (a);
+ERROR 42S22: Unknown column 'a' in 'partition function'
+create table t1 (a int)
+partition by range (a)
+(partition p0 values less than (1));
+alter table t1 add partition (partition p1 values less than (a));
+ERROR 42S22: Unknown column 'a' in 'partition function'
+alter table t1 add partition 
+(partition p1 values less than ((select count(*) from t1)));
+ERROR HY000: This partition function is not allowed
+drop table t1;
+create table t1 (a int)
 engine = x
 partition by key (a);
 Warnings:

mysql-test/t/partition_error.test

@@ -8,6 +8,28 @@
 drop table if exists t1;
 --enable_warnings
 
+#
+# Bug 18198: Partitions: Too flexible functions
+#
+-- error ER_PARTITION_FUNCTION_IS_NOT_ALLOWED
+create table t1 (a int)
+partition by range (a)
+(partition p0 values less than ((select count(*) from t1)));
+-- error 1054
+create table t1 (a int)
+partition by range (a)
+(partition p0 values less than (a);
+
+create table t1 (a int)
+partition by range (a)
+(partition p0 values less than (1));
+-- error 1054
+alter table t1 add partition (partition p1 values less than (a));
+-- error ER_PARTITION_FUNCTION_IS_NOT_ALLOWED
+alter table t1 add partition 
+(partition p1 values less than ((select count(*) from t1)));
+drop table t1;
+
 #
 # Bug 20397: Partitions: Crash when using non-existing engine
 #

sql/sql_yacc.yy

@@ -3616,6 +3616,7 @@ part_bit_expr:
         {
           Item *part_expr= $1;
           bool not_corr_func;
+          bool part_expression_ok= TRUE;
           LEX *lex= Lex;
           THD *thd= YYTHD;
           longlong item_value;
@@ -3633,13 +3634,19 @@ part_bit_expr:
             mem_alloc_error(sizeof(part_elem_value));
             YYABORT;
           }
-
+          part_expr->walk(&Item::check_partition_func_processor, 0,
+                          (byte*)(&part_expression_ok));
+          if (!part_expression_ok)
+          {
+            my_error(ER_PARTITION_FUNCTION_IS_NOT_ALLOWED, MYF(0));
+            YYABORT;
+          }
           if (part_expr->fix_fields(YYTHD, (Item**)0) ||
               ((context->table_list= save_list), FALSE) ||
               (!part_expr->const_item()) ||
               (!lex->safe_to_cache_query))
           {
-            yyerror(ER(ER_NO_CONST_EXPR_IN_RANGE_OR_LIST_ERROR));
+            my_error(ER_NO_CONST_EXPR_IN_RANGE_OR_LIST_ERROR, MYF(0));
             YYABORT;
           }
           thd->where= save_where;