Fixed bug in query cache after temporary table creation.

Docs/manual.texi:
  change log entry
mysql-test/r/query_cache.result:
  bug test suite
mysql-test/t/query_cache.test:
  bug test suite

Docs/manual.texi

@@ -50147,6 +50147,8 @@ each individual 4.0.x release.
 
 @itemize @bullet
 @item
+Fixed bug in query cache after temporary table creation.
+@item
 Fixed bug in multi-table @code{UPDATE}: when updating a table,
 @code{do_select()} became confused about reading records from a cache.
 @item

mysql-test/r/query_cache.result

@@ -506,3 +506,23 @@ set GLOBAL query_cache_size=1900;
 show global variables like "query_cache_size";
 Variable_name	Value
 query_cache_size	1024
+set GLOBAL query_cache_size=1048576;
+create table t1 (i int not null);
+create table t2 (i int not null);
+select * from t1;
+i
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	1
+create temporary table t3 (i int not null);
+select * from t2;
+i
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	2
+select * from t3;
+i
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	2
+drop table t1, t2, t3;

mysql-test/t/query_cache.test

@@ -352,3 +352,18 @@ set GLOBAL query_cache_size=1700;
 set GLOBAL query_cache_size=1800;
 set GLOBAL query_cache_size=1900;
 show global variables like "query_cache_size";
+
+#
+# Temporary tables
+#
+set GLOBAL query_cache_size=1048576;
+create table t1 (i int not null);
+create table t2 (i int not null);
+select * from t1;
+show status like "Qcache_queries_in_cache";
+create temporary table t3 (i int not null);
+select * from t2;
+show status like "Qcache_queries_in_cache";
+select * from t3;
+show status like "Qcache_queries_in_cache";
+drop table t1, t2, t3;

sql/sql_cache.cc

@@ -2395,7 +2395,6 @@ TABLE_COUNTER_TYPE Query_cache::is_cacheable(THD *thd, uint32 query_len,
   DBUG_ENTER("Query_cache::is_cacheable");
 
   if (lex->sql_command == SQLCOM_SELECT &&
-      thd->temporary_tables == 0 &&
       (thd->variables.query_cache_type == 1 ||
        (thd->variables.query_cache_type == 2 && (lex->select->options &
 						 OPTION_TO_QUERY_CACHE))) &&
@@ -2416,9 +2415,11 @@ TABLE_COUNTER_TYPE Query_cache::is_cacheable(THD *thd, uint32 query_len,
       has_transactions = (has_transactions ||
 			  tables_used->table->file->has_transactions());
 
-      if (tables_used->table->db_type == DB_TYPE_MRG_ISAM)
+      if (tables_used->table->db_type == DB_TYPE_MRG_ISAM ||
+	  tables_used->table->tmp_table != NO_TMP_TABLE)
       {
-	DBUG_PRINT("qcache", ("select not cacheable: used MRG_ISAM table(s)"));
+	DBUG_PRINT("qcache", 
+		   ("select not cacheable: used MRG_ISAM or temporary table(s)"));
 	DBUG_RETURN(0);
       }
       if (tables_used->table->db_type == DB_TYPE_MRG_MYISAM)