Bug #31157: crash when select+order by the avg of some field within the group by

The uncacheable flag should be set at fix_fields() stage.
Fixed by moving the flag setting to match the one in 5.1

mysql-test/r/query_cache.result

@@ -1732,4 +1732,18 @@ Variable_name	Value
 Qcache_queries_in_cache	1
 drop database db2;
 drop database db3;
+CREATE TABLE t1 (a ENUM('rainbow'));
+INSERT INTO t1 VALUES (),(),(),(),();
+SELECT 1 FROM t1 GROUP BY (SELECT 1 FROM t1 ORDER BY AVG(LAST_INSERT_ID()));
+1
+1
+DROP TABLE t1;
+CREATE TABLE t1 (a LONGBLOB);
+INSERT INTO t1 SET a = 'aaaa';
+INSERT INTO t1 SET a = 'aaaa';
+SELECT 1 FROM t1 GROUP BY 
+(SELECT LAST_INSERT_ID() FROM t1 ORDER BY MIN(a) ASC LIMIT 1);
+1
+1
+DROP TABLE t1;
 End of 5.1 tests

mysql-test/t/query_cache.test

@@ -1333,4 +1333,21 @@ show status like 'Qcache_queries_in_cache';
 drop database db2;
 drop database db3;
 
+#
+# Bug #31157: Crash when select+order by the avg of some field within the
+# group by
+#
+
+CREATE TABLE t1 (a ENUM('rainbow'));
+INSERT INTO t1 VALUES (),(),(),(),();
+SELECT 1 FROM t1 GROUP BY (SELECT 1 FROM t1 ORDER BY AVG(LAST_INSERT_ID()));
+DROP TABLE t1;
+CREATE TABLE t1 (a LONGBLOB);
+INSERT INTO t1 SET a = 'aaaa';
+INSERT INTO t1 SET a = 'aaaa';
+SELECT 1 FROM t1 GROUP BY 
+  (SELECT LAST_INSERT_ID() FROM t1 ORDER BY MIN(a) ASC LIMIT 1);
+DROP TABLE t1;
+
+
 --echo End of 5.1 tests

sql/item_func.cc

@@ -3624,10 +3624,17 @@ longlong Item_func_last_insert_id::val_int()
     thd->first_successful_insert_id_in_prev_stmt= value;
     return value;
   }
-  thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT);
   return thd->read_first_successful_insert_id_in_prev_stmt();
 }
 
+
+bool Item_func_last_insert_id::fix_fields(THD *thd, Item **ref)
+{
+  thd->lex->uncacheable(UNCACHEABLE_SIDEEFFECT);
+  return Item_int_func::fix_fields(thd, ref);
+}
+
+
 /* This function is just used to test speed of different functions */
 
 longlong Item_func_benchmark::val_int()

sql/item_func.h

@@ -935,6 +935,7 @@ public:
     if (arg_count)
       max_length= args[0]->max_length;
   }
+  bool fix_fields(THD *thd, Item **ref);
 };