fixed comparation of tables/database names with --lower_case_table_names (BUG#2880)

mysql-test/r/lowercase_table.result:
  test of multi-update/multi-delete
mysql-test/t/lowercase_table.test:
  test of multi-update/multi-delete
sql/sql_cache.cc:
  correct databese names comparation
sql/sql_parse.cc:
  correct table names comparation in multi-delete

mysql-test/r/lowercase_table.result

@@ -42,3 +42,10 @@ select count(bags.a) from t1 as Bags;
 count(bags.a)
 0
 drop table t1;
+create table t1 (a int);
+create table t2 (a int);
+delete p1.*,P2.* from t1 as p1, t2 as p2 where p1.a=P2.a;
+delete P1.*,p2.* from t1 as P1, t2 as P2 where P1.a=p2.a;
+update t1 as p1, t2 as p2 SET p1.a=1,P2.a=1 where p1.a=P2.a;
+update t1 as P1, t2 as P2 SET P1.a=1,p2.a=1 where P1.a=p2.a;
+drop table t1,t2;

mysql-test/r/lowercase_table_qcache.result

+set GLOBAL query_cache_size=1355776;
+drop database if exists MySQLtesT;
+create database MySQLtesT;
+create table MySQLtesT.t1 (a int);
+select * from MySQLtesT.t1;
+a
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	1
+drop database mysqltest;
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+use MySQL;
+select * from db;
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+use test;
+select * from MySQL.db;
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	0
+set GLOBAL query_cache_size=0;

mysql-test/t/lowercase_table.test

@@ -30,3 +30,14 @@ select count(*) from t1;
 select count(T1.a) from t1;
 select count(bags.a) from t1 as Bags;
 drop table t1;
+
+#
+# multiupdate/delete & --lower-case-table-names
+#
+create table t1 (a int);
+create table t2 (a int);
+delete p1.*,P2.* from t1 as p1, t2 as p2 where p1.a=P2.a;
+delete P1.*,p2.* from t1 as P1, t2 as P2 where P1.a=p2.a;
+update t1 as p1, t2 as p2 SET p1.a=1,P2.a=1 where p1.a=P2.a;
+update t1 as P1, t2 as P2 SET P1.a=1,p2.a=1 where P1.a=p2.a;
+drop table t1,t2;

mysql-test/t/lowercase_table_qcache-master.opt

+--lower_case_table_names

mysql-test/t/lowercase_table_qcache.test

+-- source include/have_query_cache.inc
+#
+# Test of query cache with --lower-case-table-names
+#
+set GLOBAL query_cache_size=1355776;
+
+--disable_warnings
+drop database if exists MySQLtesT;
+--enable_warnings
+
+create database MySQLtesT;
+create table MySQLtesT.t1 (a int);
+select * from MySQLtesT.t1;
+show status like "Qcache_queries_in_cache";
+drop database mysqltest;
+show status like "Qcache_queries_in_cache";
+
+use MySQL;
+disable_result_log;
+select * from db;
+enable_result_log;
+show status like "Qcache_queries_in_cache";
+use test;
+disable_result_log;
+select * from MySQL.db;
+enable_result_log;
+show status like "Qcache_queries_in_cache";
+
+set GLOBAL query_cache_size=0;
\ No newline at end of file

sql/sql_cache.cc

@@ -1228,7 +1228,12 @@ void Query_cache::invalidate(char *db)
 	do
 	{
 	  next= curr->next;
-	  if (strcmp(db, (char*)(curr->table()->db())) == 0)
+	  /*
+	    table_alias_charset used here because it depends of
+	    lower_case_table_names variable
+	  */
+	  if (my_strcasecmp(table_alias_charset, db, 
+			    (char*)(curr->table()->db())) == 0)
 	    invalidate_table(curr);
 	  /*
 	    invalidate_table can freed block on which point 'next' (if
@@ -2562,20 +2567,15 @@ TABLE_COUNTER_TYPE Query_cache::is_cacheable(THD *thd, uint32 query_len,
 			  tables_used->db, tables_used->table->db_type));
       *tables_type|= tables_used->table->file->table_cache_type();
 
+      /*
+	table_alias_charset used here because it depends of
+	lower_case_table_names variable
+      */
       if (tables_used->table->db_type == DB_TYPE_MRG_ISAM ||
 	  tables_used->table->tmp_table != NO_TMP_TABLE ||
 	  (tables_used->db_length == 5 &&
-#ifdef FN_NO_CASE_SENCE
-	   my_strnncoll(system_charset_info, (uchar*)tables_used->db, 6,
-					     (uchar*)"mysql",6) == 0
-#else
-	   tables_used->db[0]=='m' &&
-	   tables_used->db[1]=='y' &&
-	   tables_used->db[2]=='s' &&
-	   tables_used->db[3]=='q' &&
-	   tables_used->db[4]=='l'
-#endif
-	   ))
+	   my_strnncoll(table_alias_charset, (uchar*)tables_used->db, 6,
+			(uchar*)"mysql",6) == 0))
       {
 	DBUG_PRINT("qcache", 
 		   ("select not cacheable: used MRG_ISAM, temporary or system table(s)"));

sql/sql_parse.cc

@@ -2670,8 +2670,8 @@ mysql_execute_command(THD *thd)
       TABLE_LIST *walk;
       for (walk= (TABLE_LIST*) tables; walk; walk= walk->next)
       {
-	if (!strcmp(auxi->real_name, walk->alias) &&
-	    !strcmp(walk->db, auxi->db))
+	if (!my_strcasecmp(table_alias_charset, auxi->alias, walk->alias) &&
+	    !my_strcasecmp(table_alias_charset, walk->db, auxi->db))
 	  break;
       }
       if (!walk)