Fixed MDEV-5617: mysqld crashes when running a query with ONLY_FULL_GROUP_BY

Problem was that we used cache_table in some cases where it was not initialized

mysql-test/r/func_group.result:
  Added test case
mysql-test/t/func_group.test:
  Added test case
sql/item.cc:
  Don't use cached_table if not set
sql/item_sum.cc:
  Don't use cached_table

mysql-test/r/func_group.result

@@ -1458,6 +1458,8 @@ DROP TABLE derived1;
 DROP TABLE D;
 CREATE TABLE t1 (a INT, b INT);
 INSERT INTO t1 VALUES (1,1), (1,2), (1,3);
+CREATE TABLE t2 (b INT);
+INSERT INTO t2 VALUES (3),(4);
 SET SQL_MODE='ONLY_FULL_GROUP_BY';
 SELECT COUNT(*) FROM t1;
 COUNT(*)
@@ -1473,12 +1475,19 @@ COUNT(*)
 SELECT COUNT(*), (SELECT count(*) FROM t1 inr WHERE inr.a = outr.a) 
 FROM t1 outr;
 ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause
+SELECT COUNT(*) FROM t1 outr, (SELECT b, count(*) FROM t2) as t3;
+ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause
+SELECT COUNT(*) FROM t1 outr where (1,1) in (SELECT a, count(*) FROM t2);
+COUNT(*)
+0
 SELECT COUNT(*) FROM t1 a JOIN t1 outr 
 ON a.a= (SELECT count(*) FROM t1 inr WHERE inr.a = outr.a);
 COUNT(*)
 0
+SELECT * FROM (SELECT a FROM t1 GROUP BY a) sq JOIN t2 ON a = b;
+a	b
 SET SQL_MODE=default;
-DROP TABLE t1;
+DROP TABLE t1,t2;
 End of 5.0 tests
 #
 # BUG#47280 - strange results from count(*) with order by multiple 

mysql-test/t/func_group.test

@@ -981,10 +981,13 @@ DROP TABLE D;
 #
 # Bug #39656: Behaviour different for agg functions with & without where -
 # ONLY_FULL_GROUP_BY
+# MDEV-5617 mysqld crashes when running a query with ONLY_FULL_GROUP_BY
 #
 
 CREATE TABLE t1 (a INT, b INT);
 INSERT INTO t1 VALUES (1,1), (1,2), (1,3);
+CREATE TABLE t2 (b INT);
+INSERT INTO t2 VALUES (3),(4);
 
 SET SQL_MODE='ONLY_FULL_GROUP_BY';
 
@@ -1000,11 +1003,18 @@ SELECT COUNT(*) FROM t1 a JOIN t1 b ON a.a= b.a;
 SELECT COUNT(*), (SELECT count(*) FROM t1 inr WHERE inr.a = outr.a) 
   FROM t1 outr;
 
+--error ER_MIX_OF_GROUP_FUNC_AND_FIELDS
+SELECT COUNT(*) FROM t1 outr, (SELECT b, count(*) FROM t2) as t3;
+
+SELECT COUNT(*) FROM t1 outr where (1,1) in (SELECT a, count(*) FROM t2);
+
 SELECT COUNT(*) FROM t1 a JOIN t1 outr 
   ON a.a= (SELECT count(*) FROM t1 inr WHERE inr.a = outr.a);
 
+SELECT * FROM (SELECT a FROM t1 GROUP BY a) sq JOIN t2 ON a = b;
+
 SET SQL_MODE=default;
-DROP TABLE t1;
+DROP TABLE t1,t2;
 
 
 ###

sql/item.cc

@@ -5230,8 +5230,8 @@ bool Item_field::fix_fields(THD *thd, Item **reference)
   if (any_privileges)
   {
     char *db, *tab;
-    db= cached_table->get_db_name();
-    tab= cached_table->get_table_name();
+    db=  field->table->s->db.str;
+    tab= field->table->s->table_name.str;
     if (!(have_privileges= (get_column_grant(thd, &field->table->grant,
                                              db, tab, field_name) &
                             VIEW_ANY_ACL)))
@@ -5252,7 +5252,12 @@ bool Item_field::fix_fields(THD *thd, Item **reference)
     marker= thd->lex->current_select->cur_pos_in_select_list;
   }
 mark_non_agg_field:
-  if (fixed && thd->variables.sql_mode & MODE_ONLY_FULL_GROUP_BY)
+  /*
+    table->pos_in_table_list can be 0 when fixing partition functions
+    or virtual fields.
+  */
+  if (fixed && (thd->variables.sql_mode & MODE_ONLY_FULL_GROUP_BY) &&
+      field->table->pos_in_table_list)
   {
     /*
       Mark selects according to presence of non aggregated fields.
@@ -5265,7 +5270,7 @@ bool Item_field::fix_fields(THD *thd, Item **reference)
       (the current level) or a stub added by non-SELECT queries.
     */
     SELECT_LEX *select_lex= cached_table ? 
-      cached_table->select_lex : context->select_lex;
+      cached_table->select_lex : field->table->pos_in_table_list->select_lex;
     if (!thd->lex->in_sum_func)
       select_lex->set_non_agg_field_used(true);
     else
@@ -8234,7 +8239,7 @@ int Item_default_value::save_in_field(Field *field_arg, bool no_conversions)
 
       if (context->error_processor == &view_error_processor)
       {
-        TABLE_LIST *view= cached_table->top_table();
+        TABLE_LIST *view= field_arg->table->pos_in_table_list->top_table();
         push_warning_printf(field_arg->table->in_use,
                             MYSQL_ERROR::WARN_LEVEL_WARN,
                             ER_NO_DEFAULT_FOR_VIEW_FIELD,

sql/item_sum.cc

@@ -261,7 +261,7 @@ bool Item_sum::check_sum_func(THD *thd, Item **ref)
     List_iterator<Item_field> of(outer_fields);
     while ((field= of++))
     {
-      SELECT_LEX *sel= field->cached_table->select_lex;
+      SELECT_LEX *sel= field->field->table->pos_in_table_list->select_lex;
       if (sel->nest_level < aggr_level)
       {
         if (in_sum_func)