Some optimization in SET NAMES

mysql-test/r/ctype_collate.result:
  SET NAMES charset COLLATE collation is new syntax
mysql-test/r/variables.result:
  SET NAMES charset COLLATE collation is new syntax
mysql-test/t/ctype_collate.test:
  SET NAMES charset COLLATE collation is new syntax
mysql-test/t/variables.test:
  SET NAMES charset COLLATE collation is new syntax

mysql-test/r/ctype_collate.result

@@ -546,14 +546,14 @@ client_collation	koi8r_general_ci
 SELECT charset('a'),collation('a'),coercibility('a'),'a'='A';
 charset('a')	collation('a')	coercibility('a')	'a'='A'
 latin1	latin1_swedish_ci	3	1
-SET COLLATION koi8r_bin;
+SET NAMES koi8r COLLATE koi8r_bin;
 SHOW VARIABLES LIKE 'client_collation';
 Variable_name	Value
 client_collation	koi8r_bin
 SELECT charset('a'),collation('a'),coercibility('a'),'a'='A';
 charset('a')	collation('a')	coercibility('a')	'a'='A'
 latin1	latin1_swedish_ci	3	1
-SET COLLATION DEFAULT;
+SET NAMES koi8r COLLATE DEFAULT;
 SHOW VARIABLES LIKE 'client_collation';
 Variable_name	Value
 client_collation	koi8r_general_ci

mysql-test/r/variables.result

@@ -155,18 +155,10 @@ set net_buffer_length=2000000000;
 show variables like 'net_buffer_length';
 Variable_name	Value
 net_buffer_length	1048576
-set GLOBAL character set cp1251_koi8;
-show global variables like "client_collation";
-Variable_name	Value
-client_collation	cp1251_bulgarian_ci
 set character set cp1251_koi8;
 show variables like "client_collation";
 Variable_name	Value
 client_collation	cp1251_bulgarian_ci
-set global character set default, session character set default;
-show variables like "client_collation";
-Variable_name	Value
-client_collation	latin1_swedish_ci
 select @@timestamp>0;
 @@timestamp>0
 1
@@ -195,10 +187,6 @@ set GLOBAL table_type=DEFAULT;
 Variable 'table_type' doesn't have a default value
 set client_collation=UNKNOWN_CHARACTER_SET;
 Unknown character set: 'UNKNOWN_CHARACTER_SET'
-set character set unknown;
-Unknown character set: 'unknown'
-set character set 0;
-Wrong argument type to variable 'client_collation'
 set global autocommit=1;
 Variable 'autocommit' is a LOCAL variable and can't be used with SET GLOBAL
 select @@global.timestamp;

mysql-test/t/ctype_collate.test

@@ -143,10 +143,10 @@ SELECT charset('a'),collation('a'),coercibility('a'),'a'='A';
 SET NAMES koi8r;
 SHOW VARIABLES LIKE 'client_collation';
 SELECT charset('a'),collation('a'),coercibility('a'),'a'='A';
-SET COLLATION koi8r_bin;
+SET NAMES koi8r COLLATE koi8r_bin;
 SHOW VARIABLES LIKE 'client_collation';
 SELECT charset('a'),collation('a'),coercibility('a'),'a'='A';
-SET COLLATION DEFAULT;
+SET NAMES koi8r COLLATE DEFAULT;
 SHOW VARIABLES LIKE 'client_collation';
 SELECT charset('a'),collation('a'),coercibility('a'),'a'='A';
 SET NAMES DEFAULT;

mysql-test/t/variables.test

@@ -91,12 +91,8 @@ show variables like 'net_buffer_length';
 set net_buffer_length=2000000000;
 show variables like 'net_buffer_length';
 
-set GLOBAL character set cp1251_koi8;
-show global variables like "client_collation";
 set character set cp1251_koi8;
 show variables like "client_collation";
-set global character set default, session character set default;
-show variables like "client_collation";
 select @@timestamp>0;
 
 set @@rand_seed1=10000000,@@rand_seed2=1000000;
@@ -124,10 +120,6 @@ set SESSION query_cache_size=10000;
 set GLOBAL table_type=DEFAULT;
 --error 1115
 set client_collation=UNKNOWN_CHARACTER_SET;
---error 1115
-set character set unknown;
---error 1232
-set character set 0;
 --error 1228
 set global autocommit=1;
 --error 1228

sql/set_var.cc

@@ -1175,7 +1175,7 @@ static my_old_conv old_conv[]=
 	{	NULL			,	NULL		}
 };
 
-static CHARSET_INFO *get_old_charset_by_name(const char *name)
+CHARSET_INFO *get_old_charset_by_name(const char *name)
 {
   my_old_conv *c;
  
@@ -1662,22 +1662,23 @@ int set_var_password::update(THD *thd)
 
 int set_var_client_collation::check(THD *thd)
 {
+  client_charset= client_charset ? client_charset : thd->db_charset;
+  client_collation= client_collation ? client_collation : client_charset;
+  if (!my_charset_same(client_charset, client_collation))
+  {
+    my_error(ER_COLLATION_CHARSET_MISMATCH, MYF(0),
+	     client_collation->name, client_charset->csname);
+    return -1;
+  }
   return 0;
 }
 
 int set_var_client_collation::update(THD *thd)
 {
-#if 0
-  if (var->type == OPT_GLOBAL)
-    global_system_variables.thd_charset= var->save_result.charset;
-  else
-#endif
-  {
-    thd->variables.thd_charset= client_collation;
-    thd->variables.convert_result_charset= convert_result_charset;
-    thd->protocol_simple.init(thd);
-    thd->protocol_prep.init(thd);
-  }
+  thd->variables.thd_charset= client_collation;
+  thd->variables.convert_result_charset= convert_result_charset;
+  thd->protocol_simple.init(thd);
+  thd->protocol_prep.init(thd);
   return 0;
 }
 

sql/set_var.h

@@ -530,11 +530,14 @@ public:
 
 class set_var_client_collation: public set_var_base
 {
+  CHARSET_INFO *client_charset;
   CHARSET_INFO *client_collation;
   my_bool convert_result_charset;
 public:
-  set_var_client_collation(CHARSET_INFO *coll_arg ,my_bool conv_arg)
-    :client_collation(coll_arg), convert_result_charset(conv_arg)
+  set_var_client_collation(CHARSET_INFO *cset_arg,
+  			   CHARSET_INFO *coll_arg ,my_bool conv_arg)
+    :client_charset(cset_arg), client_collation(coll_arg),
+     convert_result_charset(conv_arg)
   {}
   int check(THD *thd);
   int update(THD *thd);
@@ -552,3 +555,4 @@ int sql_set_variables(THD *thd, List<set_var_base> *var_list);
 void fix_delay_key_write(THD *thd, enum_var_type type);
 
 extern sys_var_str sys_charset;
+CHARSET_INFO *get_old_charset_by_name(const char *old_name);

sql/sql_yacc.yy

@@ -646,6 +646,8 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 	opt_collate
 	charset_name
 	charset_name_or_default
+	old_or_new_charset_name
+	old_or_new_charset_name_or_default
 	collation_name
 	collation_name_or_default
 
@@ -1354,6 +1356,24 @@ charset_name_or_default:
 	charset_name { $$=$1;   }
 	| DEFAULT    { $$=NULL; } ;
 
+
+old_or_new_charset_name:
+	ident_or_text
+	{
+	  if (!($$=get_charset_by_csname($1.str,MY_CS_PRIMARY,MYF(0))) &&
+	      !($$=get_old_charset_by_name($1.str)))
+	  {
+	    net_printf(YYTHD,ER_UNKNOWN_CHARACTER_SET,$1.str);
+	    YYABORT;
+	  }
+	}
+	| BINARY { $$= &my_charset_bin; }
+	;
+
+old_or_new_charset_name_or_default:
+	old_or_new_charset_name { $$=$1;   }
+	| DEFAULT    { $$=NULL; } ;
+
 collation_name:
 	ident_or_text
 	{
@@ -1366,7 +1386,7 @@ collation_name:
 
 opt_collate:
 	/* empty */	{ $$=NULL; }
-	| COLLATE_SYM collation_name { $$=$2; }
+	| COLLATE_SYM collation_name_or_default { $$=$2; }
 	;
 
 collation_name_or_default:
@@ -4383,56 +4403,15 @@ option_value:
 						find_sys_var("tx_isolation"),
 						new Item_int((int32) $4)));
 	  }
-	| charset set_expr_or_default
+	| charset old_or_new_charset_name_or_default
 	{
-	  THD *thd= YYTHD;
-	  LEX *lex= &thd->lex;
-	  if (!$2)
-	  {
-	    CHARSET_INFO *cl= thd->db_charset;
-	    $2= new Item_string(cl->name, strlen(cl->name), &my_charset_latin1);
-	  }
-	  lex->var_list.push_back(new set_var(lex->option_type,
-					      find_sys_var("client_collation"),
-					      $2));
+	  LEX *lex= Lex;
+	  lex->var_list.push_back(new set_var_client_collation($2,NULL,1));
 	}
 	| NAMES_SYM charset_name_or_default opt_collate
 	{
-	  THD* thd= YYTHD;
-	  LEX *lex= &thd->lex;
-	  CHARSET_INFO *cs= $2 ? $2 : thd->db_charset;
-	  CHARSET_INFO *cl= $3 ? $3 : cs;
-
-	  if (!my_charset_same(cs,cl))
-	  {
-	      net_printf(YYTHD,ER_COLLATION_CHARSET_MISMATCH, 
-		         cl->name,cs->csname);
-	      YYABORT;
-	  }
-	  lex->var_list.push_back(new set_var_client_collation(cl,1));
-	}
-	| COLLATION_SYM collation_name_or_default
-	{
-	  THD* thd= YYTHD;
-	  LEX *lex= &thd->lex;
-	  CHARSET_INFO *cs= thd->variables.thd_charset;
-	  CHARSET_INFO *cl= $2;
-
-	  if (!cl)
-	  {
-	    if (!(cl=get_charset_by_csname(cs->csname,MY_CS_PRIMARY,MYF(0))))
-	    {
-	      net_printf(YYTHD,ER_UNKNOWN_CHARACTER_SET,"DEFAULT");
-	      YYABORT;
-	    }
-	  }
-	  else if (!my_charset_same(cs,cl))
-	  {
-	      net_printf(YYTHD,ER_COLLATION_CHARSET_MISMATCH, 
-		         cl->name,cs->csname);
-	      YYABORT;
-	  }
-	  lex->var_list.push_back(new set_var_client_collation(cl,1));
+	  LEX *lex= Lex;
+	  lex->var_list.push_back(new set_var_client_collation($2,$3,1));
 	}
 	| PASSWORD equal text_or_password
 	  {