Bug#35338776: Failure in find_item_in_list with unknown column in field list

The problem is that when a column reference given by table name and
column name is looked up in the function find_item_in_list(), we
ignored that the searched item may not have a table name, as it is
not yet resolved. Now, we should really only search for strict alias
names in find_item_in_list(), however removing this support would be
a much larger change, so we restrict the fix to an explicit check for
a null table name in the searched item.

Change-Id: I216f478efe72545e30c61e56919419db8b81f60d

Author: roylyseng

mysql-test/r/subquery_bugs.result

@@ -2310,3 +2310,6 @@ Warnings:
 Note	1003	/* select#1 */ select (/* select#4 */ select (`test`.`t`.`f` = 1) AS `f` from `test`.`t`) AS `f` from `test`.`t` `t1` join `test`.`t` where false
 DROP VIEW v;
 DROP TABLE t;
+# Bug#35338776: Failure in find_item_in_list with unknown column 
+SELECT(SELECT SIN(a.c7)),c7;
+ERROR 42S22: Unknown column 'a.c7' in 'field list'

mysql-test/t/subquery_bugs.test

@@ -1943,3 +1943,9 @@ eval explain $query;
 
 DROP VIEW v;
 DROP TABLE t;
+
+--echo # Bug#35338776: Failure in find_item_in_list with unknown column 
+
+--error ER_BAD_FIELD_ERROR
+SELECT(SELECT SIN(a.c7)),c7;
+

sql/sql_base.cc

@@ -8144,8 +8144,9 @@ bool find_item_in_list(THD *thd, Item *find, mem_root_deque<Item *> *items,
         */
         if (!my_strcasecmp(system_charset_info, item_field->field_name,
                            find_ident->field_name) &&
-            !my_strcasecmp(table_alias_charset, item_field->table_name,
-                           find_ident->table_name) &&
+            (item_field->table_name != nullptr &&
+             !my_strcasecmp(table_alias_charset, item_field->table_name,
+                            find_ident->table_name)) &&
             (find_ident->db_name == nullptr ||
              (item_field->db_name != nullptr &&
               !strcmp(item_field->db_name, find_ident->db_name)))) {