Fix for a bug #2422, where CONVERT(expr, cast) was masked by

CONVERT(expr, expr, expr);

mysql-test/r/cast.result

@@ -33,6 +33,9 @@ cast("2001-1-1" as DATE)	cast("2001-1-1" as DATETIME)
 select cast("1:2:3" as TIME);
 cast("1:2:3" as TIME)
 01:02:03
+select CONVERT("2004-01-22 21:45:33",DATE);
+CONVERT("2004-01-22 21:45:33",DATE)
+2004-01-22
 set names binary;
 select cast(_latin1'test' as char character set latin2);
 cast(_latin1'test' as char character set latin2)

mysql-test/t/cast.test

@@ -13,6 +13,7 @@ select cast(5 as unsigned) -6.0;
 select cast("A" as binary) = "a", cast(BINARY "a" as CHAR) = "A";
 select cast("2001-1-1" as DATE), cast("2001-1-1" as DATETIME);
 select cast("1:2:3" as TIME);
+select CONVERT("2004-01-22 21:45:33",DATE);
 
 #
 # Character set convertion

mysql-test/t/mysqldump.test

@@ -6,7 +6,7 @@ DROP TABLE IF EXISTS t1, `"t"1`;
 
 CREATE TABLE t1(a int);
 INSERT INTO t1 VALUES (1), (2);
---exec $MYSQL_DUMP --disable-quote --skip-all --skip-comments -X test t1
+--exec $MYSQL_DUMP --skip-all --skip-comments -X test t1
 DROP TABLE t1;
 
 #
@@ -16,7 +16,7 @@ DROP TABLE t1;
 CREATE TABLE t1 (a decimal(240, 20));
 INSERT INTO t1 VALUES ("1234567890123456789012345678901234567890"),
 ("0987654321098765432109876543210987654321");
---exec $MYSQL_DUMP --disable-quote --skip-comments test t1
+--exec $MYSQL_DUMP --skip-comments test t1
 DROP TABLE t1;
 
 #
@@ -28,12 +28,12 @@ INSERT INTO t1 VALUES (-9e999999);
 # The following replaces is here because some systems replaces the above
 # double with '-inf' and others with MAX_DOUBLE
 --replace_result (-1.79769313486232e+308) (RES) (NULL) (RES)
---exec $MYSQL_DUMP --disable-quote --skip-comments test t1
+--exec $MYSQL_DUMP  --skip-comments test t1
 DROP TABLE t1;
 
 CREATE TABLE t1(a int, b text, c varchar(3));
 INSERT INTO t1 VALUES (1, "test", "tes"), (2, "TEST", "TES");
---exec $MYSQL_DUMP --disable-quote --skip-all --skip-comments -X test t1
+--exec $MYSQL_DUMP  --skip-all --skip-comments -X test t1
 DROP TABLE t1;
 
 #
@@ -42,7 +42,7 @@ DROP TABLE t1;
 
 CREATE TABLE t1 (`a"b"` char(2));
 INSERT INTO t1 VALUES ("1\""), ("\"2");
---exec $MYSQL_DUMP --disable-quote --skip-all --skip-comments -X test t1
+--exec $MYSQL_DUMP  --skip-all --skip-comments -X test t1
 DROP TABLE t1;
 
 #
@@ -51,5 +51,5 @@ DROP TABLE t1;
 
 CREATE TABLE t1 (a  VARCHAR(255)) DEFAULT CHARSET koi8r;
 INSERT INTO t1  VALUES (_koi8r x'C1C2C3C4C5');
---exec $MYSQL_DUMP --disable-quote --skip-comments test t1
+--exec $MYSQL_DUMP  --skip-comments test t1
 DROP TABLE t1;

sql/sql_yacc.yy

@@ -664,7 +664,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 
 %type <ha_rkey_mode> handler_rkey_mode
 
-%type <cast_type> cast_type cast_type_finalize
+%type <cast_type> cast_type
 
 %type <udf_type> udf_func_type
 
@@ -3003,11 +3003,7 @@ in_sum_expr:
 	  $$= $3;
 	};
 
-cast_type_init:
-	{ Lex->charset= NULL; Lex->length= (char*)0; }
-	;
-
-cast_type_finalize:
+cast_type:
 	BINARY			{ $$=ITEM_CAST_BINARY; }
 	| CHAR_SYM opt_len opt_binary	{ $$=ITEM_CAST_CHAR; }
 	| NCHAR_SYM opt_len	{ $$=ITEM_CAST_CHAR; Lex->charset= national_charset_info; }
@@ -3020,10 +3016,6 @@ cast_type_finalize:
 	| DATETIME		{ $$=ITEM_CAST_DATETIME; }
 	;
 
-cast_type:
-	cast_type_init cast_type_finalize { $$= $2; }
-	;
-
 expr_list:
 	{ Select->expr_list.push_front(new List<Item>); }
 	expr_list2