MDEV-17525: Window functions not working in ONLY_FULL_GROUP_BY mode

The ONLY_FULL_GROUP_BY mode states that for SELECT ... GROUP BY queries,
disallow SELECTing columns which are not referred to in the GROUP BY clause,
unless they are passed to an aggregate function like COUNT() or MAX().
This holds only for the GROUP BY clause of the query.
The code also checks this for the partition clause of the window function which is
incorrect.

mysql-test/r/win.result

@@ -3326,3 +3326,40 @@ SELECT DISTINCT BIT_AND(0)  OVER (), MAX(1) FROM t1;
 BIT_AND(0)  OVER ()	MAX(1)
 0	1
 drop table t1;
+#
+# MDEV-17525: Window functions not working in ONLY_FULL_GROUP_BY mode
+#
+CREATE TABLE t1 (name CHAR(10), test CHAR(10), score TINYINT);
+INSERT INTO t1 VALUES
+('Chun', 'SQL', 75), ('Chun', 'Tuning', 73),
+('Esben', 'SQL', 43), ('Esben', 'Tuning', 31),
+('Kaolin', 'SQL', 56), ('Kaolin', 'Tuning', 88),
+('Tatiana', 'SQL', 87), ('Tatiana', 'Tuning', 83);
+SET @save_sql_mode= @@sql_mode;
+SET sql_mode = 'ONLY_FULL_GROUP_BY';
+SELECT name, test, score,
+AVG(score) OVER (PARTITION BY test) AS average_by_test
+FROM t1;
+name	test	score	average_by_test
+Chun	SQL	75	65.2500
+Chun	Tuning	73	68.7500
+Esben	SQL	43	65.2500
+Esben	Tuning	31	68.7500
+Kaolin	SQL	56	65.2500
+Kaolin	Tuning	88	68.7500
+Tatiana	SQL	87	65.2500
+Tatiana	Tuning	83	68.7500
+set @@sql_mode= @save_sql_mode;
+SELECT name, test, score,
+AVG(score) OVER (PARTITION BY test) AS average_by_test
+FROM t1;
+name	test	score	average_by_test
+Chun	SQL	75	65.2500
+Chun	Tuning	73	68.7500
+Esben	SQL	43	65.2500
+Esben	Tuning	31	68.7500
+Kaolin	SQL	56	65.2500
+Kaolin	Tuning	88	68.7500
+Tatiana	SQL	87	65.2500
+Tatiana	Tuning	83	68.7500
+drop table t1;

mysql-test/t/win.test

@@ -2092,3 +2092,28 @@ insert into t1 values (1),(2);
 SELECT DISTINCT row_number() OVER (), MAX(1) FROM t1;
 SELECT DISTINCT BIT_AND(0)  OVER (), MAX(1) FROM t1;
 drop table t1;
+
+--echo #
+--echo # MDEV-17525: Window functions not working in ONLY_FULL_GROUP_BY mode
+--echo #
+
+CREATE TABLE t1 (name CHAR(10), test CHAR(10), score TINYINT);
+
+INSERT INTO t1 VALUES
+('Chun', 'SQL', 75), ('Chun', 'Tuning', 73),
+('Esben', 'SQL', 43), ('Esben', 'Tuning', 31),
+('Kaolin', 'SQL', 56), ('Kaolin', 'Tuning', 88),
+('Tatiana', 'SQL', 87), ('Tatiana', 'Tuning', 83);
+
+SET @save_sql_mode= @@sql_mode;
+SET sql_mode = 'ONLY_FULL_GROUP_BY';
+
+SELECT name, test, score,
+  AVG(score) OVER (PARTITION BY test) AS average_by_test
+FROM t1;
+
+set @@sql_mode= @save_sql_mode;
+SELECT name, test, score,
+  AVG(score) OVER (PARTITION BY test) AS average_by_test
+FROM t1;
+drop table t1;

sql/sql_select.cc

@@ -22611,7 +22611,8 @@ setup_group(THD *thd, Ref_ptr_array ref_pointer_array, TABLE_LIST *tables,
       return 1;
     }
   }
-  if (thd->variables.sql_mode & MODE_ONLY_FULL_GROUP_BY)
+  if (thd->variables.sql_mode & MODE_ONLY_FULL_GROUP_BY &&
+      context_analysis_place == IN_GROUP_BY)
   {
     /*
       Don't allow one to use fields that is not used in GROUP BY