Bug#16084594 USER_VAR ITEM IN 'LOAD FILE QUERY' WAS NOT

PROPERLY QUOTED IN BINLOG FILE
Problem: In load data file query, User variables are allowed
inside "Into_list" and "Set_list". These user variables used
inside these two lists are not properly guarded with backticks
while server is writting into binlog. Hence user variable names
like a` cannot be used in this context.

Fix: Properly quote these variables while
writting into binlog

mysql-test/r/func_compress.result:
  changing result file
mysql-test/r/variables.result:
  changing result file
mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result:
  changing result file
sql/item_func.cc:
  Quote the user variable items

mysql-test/r/func_compress.result

@@ -11,7 +11,7 @@ explain extended select uncompress(compress(@test_compress_string));
 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 uncompress(compress((@test_compress_string))) AS `uncompress(compress(@test_compress_string))`
+Note	1003	select uncompress(compress((@`test_compress_string`))) AS `uncompress(compress(@test_compress_string))`
 select uncompressed_length(compress(@test_compress_string))=length(@test_compress_string);
 uncompressed_length(compress(@test_compress_string))=length(@test_compress_string)
 1
@@ -19,7 +19,7 @@ explain extended select uncompressed_length(compress(@test_compress_string))=len
 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 (uncompressed_length(compress((@test_compress_string))) = length((@test_compress_string))) AS `uncompressed_length(compress(@test_compress_string))=length(@test_compress_string)`
+Note	1003	select (uncompressed_length(compress((@`test_compress_string`))) = length((@`test_compress_string`))) AS `uncompressed_length(compress(@test_compress_string))=length(@test_compress_string)`
 select uncompressed_length(compress(@test_compress_string));
 uncompressed_length(compress(@test_compress_string))
 117

mysql-test/r/variables.result

@@ -77,7 +77,7 @@ explain extended select @t1:=(@t2:=1)+@t3:=4,@t1,@t2,@t3;
 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 (@t1:=((@t2:=1) + (@t3:=4))) AS `@t1:=(@t2:=1)+@t3:=4`,(@t1) AS `@t1`,(@t2) AS `@t2`,(@t3) AS `@t3`
+Note	1003	select (@t1:=((@t2:=1) + (@t3:=4))) AS `@t1:=(@t2:=1)+@t3:=4`,(@`t1`) AS `@t1`,(@`t2`) AS `@t2`,(@`t3`) AS `@t3`
 select @t5;
 @t5
 1.23456

mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result

@@ -631,7 +631,7 @@ master-bin.000001	#	Query	#	#	BEGIN
 master-bin.000001	#	Intvar	#	#	INSERT_ID=10
 master-bin.000001	#	Begin_load_query	#	#	;file_id=#;block_len=#
 master-bin.000001	#	Intvar	#	#	INSERT_ID=10
-master-bin.000001	#	Execute_load_query	#	#	use `test`; LOAD DATA INFILE '../../std_data/rpl_loaddata.dat' INTO TABLE `t4` FIELDS TERMINATED BY '\t' ENCLOSED BY '' ESCAPED BY '\\' LINES TERMINATED BY '\n' (`a`, @b) SET `b`=((@b) + `bug27417`(2)) ;file_id=#
+master-bin.000001	#	Execute_load_query	#	#	use `test`; LOAD DATA INFILE '../../std_data/rpl_loaddata.dat' INTO TABLE `t4` FIELDS TERMINATED BY '\t' ENCLOSED BY '' ESCAPED BY '\\' LINES TERMINATED BY '\n' (`a`, @`b`) SET `b`=((@`b`) + `bug27417`(2)) ;file_id=#
 master-bin.000001	#	Query	#	#	ROLLBACK
 /* the output must denote there is the query */;
 drop trigger trg_del_t2;
@@ -869,7 +869,7 @@ master-bin.000001	#	User var	#	#	@`b`=_latin1 0x3135 COLLATE latin1_swedish_ci
 master-bin.000001	#	Begin_load_query	#	#	;file_id=#;block_len=#
 master-bin.000001	#	Intvar	#	#	INSERT_ID=10
 master-bin.000001	#	User var	#	#	@`b`=_latin1 0x3135 COLLATE latin1_swedish_ci
-master-bin.000001	#	Execute_load_query	#	#	use `test`; LOAD DATA INFILE '../../std_data/rpl_loaddata.dat' INTO TABLE `t4` FIELDS TERMINATED BY '\t' ENCLOSED BY '' ESCAPED BY '\\' LINES TERMINATED BY '\n' (`a`, @b) SET `b`=((@b) + `bug27417`(2)) ;file_id=#
+master-bin.000001	#	Execute_load_query	#	#	use `test`; LOAD DATA INFILE '../../std_data/rpl_loaddata.dat' INTO TABLE `t4` FIELDS TERMINATED BY '\t' ENCLOSED BY '' ESCAPED BY '\\' LINES TERMINATED BY '\n' (`a`, @`b`) SET `b`=((@`b`) + `bug27417`(2)) ;file_id=#
 master-bin.000001	#	Query	#	#	ROLLBACK
 drop trigger trg_del_t2;
 drop table t1,t2,t3,t4,t5;

sql/item_func.cc

@@ -4725,7 +4725,7 @@ enum Item_result Item_func_get_user_var::result_type() const
 void Item_func_get_user_var::print(String *str, enum_query_type query_type)
 {
   str->append(STRING_WITH_LEN("(@"));
-  str->append(name.str,name.length);
+  append_identifier(current_thd, str, name.str, name.length);
   str->append(')');
 }
 
@@ -4826,7 +4826,7 @@ my_decimal* Item_user_var_as_out_param::val_decimal(my_decimal *decimal_buffer)
 void Item_user_var_as_out_param::print(String *str, enum_query_type query_type)
 {
   str->append('@');
-  str->append(name.str,name.length);
+  append_identifier(current_thd, str, name.str, name.length);
 }