MDEV-12681 Wrong VIEW results for CHAR(0xDF USING latin1)

mysql-test/r/ctype_utf8.result

@@ -10113,5 +10113,20 @@ DROP FUNCTION iswellformed;
 DROP TABLE allbytes;
 # End of ctype_backslash.inc
 #
+# MDEV-12681 Wrong VIEW results for CHAR(0xDF USING latin1)
+#
+SET NAMES utf8;
+SELECT CHAR(0xDF USING latin1);
+CHAR(0xDF USING latin1)
+ß
+CREATE OR REPLACE VIEW v1 AS SELECT CHAR(0xDF USING latin1) AS c;
+SHOW CREATE VIEW v1;
+View	Create View	character_set_client	collation_connection
+v1	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v1` AS select char(0xdf using latin1) AS `c`	utf8	utf8_general_ci
+SELECT * FROM v1;
+c
+ß
+DROP VIEW v1;
+#
 # End of 10.0 tests
 #

mysql-test/r/func_str.result

@@ -4530,3 +4530,24 @@ latin2_general_ci
 #
 # End of 5.6 tests
 #
+#
+# Start of 10.0 tests
+#
+#
+# MDEV-12681 Wrong VIEW results for CHAR(0xDF USING latin1)
+#
+EXPLAIN EXTENDED SELECT CHAR(0xDF USING latin1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select char(0xdf using latin1) AS `CHAR(0xDF USING latin1)`
+EXPLAIN EXTENDED SELECT CHAR(0xDF USING `binary`);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select char(0xdf) AS `CHAR(0xDF USING ``binary``)`
+EXPLAIN EXTENDED SELECT CHAR(0xDF);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
+Warnings:
+Note	1003	select char(0xdf) AS `CHAR(0xDF)`

mysql-test/t/ctype_utf8.test

@@ -1868,6 +1868,18 @@ SELECT _utf8 0x7E, _utf8 X'7E', _utf8 B'01111110';
 let $ctype_unescape_combinations=selected;
 --source include/ctype_unescape.inc
 
+--echo #
+--echo # MDEV-12681 Wrong VIEW results for CHAR(0xDF USING latin1)
+--echo #
+
+SET NAMES utf8;
+SELECT CHAR(0xDF USING latin1);
+CREATE OR REPLACE VIEW v1 AS SELECT CHAR(0xDF USING latin1) AS c;
+SHOW CREATE VIEW v1;
+SELECT * FROM v1;
+DROP VIEW v1;
+
+
 --echo #
 --echo # End of 10.0 tests
 --echo #

mysql-test/t/func_str.test

@@ -1742,3 +1742,15 @@ EXECUTE stmt;
 --echo #
 --echo # End of 5.6 tests
 --echo #
+
+--echo #
+--echo # Start of 10.0 tests
+--echo #
+
+--echo #
+--echo # MDEV-12681 Wrong VIEW results for CHAR(0xDF USING latin1)
+--echo #
+
+EXPLAIN EXTENDED SELECT CHAR(0xDF USING latin1);
+EXPLAIN EXTENDED SELECT CHAR(0xDF USING `binary`);
+EXPLAIN EXTENDED SELECT CHAR(0xDF);

sql/item_strfunc.cc

@@ -2905,6 +2905,20 @@ String *Item_func_make_set::val_str(String *str)
 }
 
 
+void Item_func_char::print(String *str, enum_query_type query_type)
+{
+  str->append(Item_func_char::func_name());
+  str->append('(');
+  print_args(str, 0, query_type);
+  if (collation.collation != &my_charset_bin)
+  {
+    str->append(C_STRING_WITH_LEN(" using "));
+    str->append(collation.collation->csname);
+  }
+  str->append(')');
+}
+
+
 String *Item_func_char::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);

sql/item_strfunc.h

@@ -702,6 +702,7 @@ class Item_func_char :public Item_str_func
     max_length= arg_count * 4;
   }
   const char *func_name() const { return "char"; }
+  void print(String *str, enum_query_type query_type);
 };