user_var.result, func_str.result, item_strfunc.cc:

  bug#7839 ncorrect collation for char(ascii('a'))

mysql-test/r/func_str.result

@@ -463,7 +463,7 @@ collation(hex(130))	coercibility(hex(130))
 latin1_swedish_ci	3
 select collation(char(130)), coercibility(hex(130));
 collation(char(130))	coercibility(hex(130))
-binary	3
+latin1_swedish_ci	3
 select collation(format(130,10)), coercibility(format(130,10));
 collation(format(130,10))	coercibility(format(130,10))
 latin1_swedish_ci	3

mysql-test/r/user_var.result

@@ -175,7 +175,7 @@ Log_name	Pos	Event_type	Server_id	Orig_log_pos	Info
 master-bin.000001	79	User var	1	79	@`a b`=_latin1 0x68656C6C6F COLLATE latin1_swedish_ci
 master-bin.000001	120	Query	1	120	use `test`; INSERT INTO t1 VALUES(@`a b`)
 master-bin.000001	184	User var	1	184	@`var1`=_latin1 0x273B616161 COLLATE latin1_swedish_ci
-master-bin.000001	226	User var	1	226	@`var2`=_binary 0x61 COLLATE binary
+master-bin.000001	226	User var	1	226	@`var2`=_latin1 0x61 COLLATE latin1_swedish_ci
 master-bin.000001	264	Query	1	264	use `test`; insert into t1 values (@var1),(@var2)
 /*!40019 SET @@session.max_insert_delayed_threads=0*/;
 SET @`a b`:=_latin1 0x68656C6C6F COLLATE `latin1_swedish_ci`;
@@ -183,7 +183,7 @@ use test;
 SET TIMESTAMP=10000;
 INSERT INTO t1 VALUES(@`a b`);
 SET @`var1`:=_latin1 0x273B616161 COLLATE `latin1_swedish_ci`;
-SET @`var2`:=_binary 0x61 COLLATE `binary`;
+SET @`var2`:=_latin1 0x61 COLLATE `latin1_swedish_ci`;
 SET TIMESTAMP=10000;
 insert into t1 values (@var1),(@var2);
 drop table t1;

sql/item_strfunc.cc

@@ -1888,6 +1888,7 @@ b1:        str->append((char)(num>>8));
 #endif
       str->append((char)num);
   }
+  str->set_charset(collation.collation);
   str->realloc(str->length());			// Add end 0 (for Purify)
   return str;
 }