Backport from mysql-6.0-codebase of:

------------------------------------------------------------
revno: 3672
committer: lars-erik.bjork@sun.com
branch nick: 48067-mysql-6.0-codebase-bugfixing
timestamp: Mon 2009-10-26 13:51:43 +0100
message:
  This is a patch for bug#48067
  "A temp table with the same name as an existing table, makes drop
  database fail"
        
  When dropping the database, mysql_rm_known_files() reads the contents
  of the database directory, and creates a TABLE_LIST object, for each
  .frm file encountered. Temporary tables, however, are not associated 
  with any .frm file.
        
  The list of tables to drop are passed to mysql_rm_table_part2().
  This method prefers temporary tables over regular tables, so if
  there is a temporary table with the same name as a regular, the
  temporary is removed, leaving the regular table intact.
  Regular tables are only deleted if there are no temporary tables
  with the same name.
        
  This fix ensures, that for all TABLE_LIST objects that are created
  by mysql_rm_known_files(), 'open_type' is set to 'OT_BASE_ONLY', to
  indicate that this is a regular table. In all cases in
  mysql_rm_table_part2() where we prefer a temporary table to a
  non-temporary table, we chek if 'open_type' equals 'OT_BASE_ONLY'.


mysql-test/r/temp_table.result:
  The expected result of the test.
mysql-test/t/temp_table.test:
  Test based on the bug report.
sql/sql_db.cc:
  For all TABLE_LIST objects that are created by mysql_rm_known_files(),
  'open_type' is set to 'OT_BASE_ONLY', to indicate that these are
  regular tables.
sql/sql_table.cc:
  Check if 'open_type' is set to 'OT_BASE_ONLY, every place a temporary table is
  preferred to a non-temporary table.

mysql-test/r/temp_table.result

@@ -210,4 +210,16 @@ UPDATE t1,t2 SET t1.a = t2.a;
 INSERT INTO t2 SELECT f1();
 DROP TABLE t1,t2,t3;
 DROP FUNCTION f1;
+#
+# Bug #48067: A temp table with the same name as an existing table, 
+#             makes drop database fail.
+#
+DROP TEMPORARY TABLE IF EXISTS bug48067.t1;
+DROP DATABASE IF EXISTS bug48067;
+CREATE DATABASE bug48067;
+CREATE TABLE bug48067.t1 (c1 int);
+INSERT INTO bug48067.t1 values (1);
+CREATE TEMPORARY TABLE bug48067.t1 (c1 int);
+DROP DATABASE bug48067;
+DROP TEMPORARY table bug48067.t1;
 End of 5.1 tests

mysql-test/t/temp_table.test

@@ -235,4 +235,19 @@ INSERT INTO t2 SELECT f1();
 DROP TABLE t1,t2,t3;
 DROP FUNCTION f1;
 
+--echo #
+--echo # Bug #48067: A temp table with the same name as an existing table, 
+--echo #             makes drop database fail.
+--echo #
+--disable_warnings
+DROP TEMPORARY TABLE IF EXISTS bug48067.t1;
+DROP DATABASE IF EXISTS bug48067;
+--enable_warnings
+CREATE DATABASE bug48067;
+CREATE TABLE bug48067.t1 (c1 int);
+INSERT INTO bug48067.t1 values (1);
+CREATE TEMPORARY TABLE bug48067.t1 (c1 int);
+DROP DATABASE bug48067;
+DROP TEMPORARY table bug48067.t1;
+
 --echo End of 5.1 tests

sql/sql_db.cc

@@ -1196,6 +1196,7 @@ static long mysql_rm_known_files(THD *thd, MY_DIR *dirp, const char *db,
       (void) filename_to_tablename(file->name, table_list->table_name,
                                  MYSQL50_TABLE_NAME_PREFIX_LENGTH +
                                  strlen(file->name) + 1);
+      table_list->open_type= OT_BASE_ONLY;
 
       /* To be able to correctly look up the table in the table cache. */
       if (lower_case_table_names)

sql/sql_table.cc

@@ -1964,7 +1964,8 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
     else
     {
       for (table= tables; table; table= table->next_local)
-        if (find_temporary_table(thd, table->db, table->table_name))
+        if (table->open_type != OT_BASE_ONLY &&
+	    find_temporary_table(thd, table->db, table->table_name))
         {
           /*
             A temporary table.
@@ -2009,8 +2010,11 @@ int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
                          table->db, table->table_name, (long) table->table,
                          table->table ? (long) table->table->s : (long) -1));
 
-    error= drop_temporary_table(thd, table);
-
+    if (table->open_type == OT_BASE_ONLY)
+      error= 1;
+    else
+      error= drop_temporary_table(thd, table);
+ 
     switch (error) {
     case  0:
       // removed temporary table