Make sure that the filename for temporary tables is built with fn_format()

so that extra slashes are handled in tmpdir. (Bug #8497)


sql/ha_heap.cc:
  use constants instead of magic integers on fn_format() calls
sql/sql_select.cc:
  Construct filename for temporary tables using fn_format() to get consistent
  filenames.
mysql-test/t/temp_table.test:
  Add new regression test
mysql-test/r/temp_table.result:
  Add new test results

mysql-test/r/temp_table.result

@@ -97,3 +97,12 @@ Variable_name	Value
 Created_tmp_disk_tables	0
 Created_tmp_tables	1
 drop table t1;
+create table t1 (a int, b int, index(a), index(b));
+create table t2 (c int auto_increment, d varchar(255), primary key (c));
+insert into t1 values (3,1),(3,2);
+insert into t2 values (NULL, 'foo'), (NULL, 'bar');
+select d, c from t1 left join t2 on b = c where a = 3 order by d;
+d	c
+bar	2
+foo	1
+drop table t1, t2;

mysql-test/t/temp_table-master.opt

+--tmpdir=$MYSQL_TEST_DIR/var//tmp

mysql-test/t/temp_table.test

@@ -89,3 +89,12 @@ flush status;
 select * from t1 group by d;
 show status like "created_tmp%tables";
 drop table t1;
+
+# Bug #8497: tmpdir with extra slashes would cause failures
+#
+create table t1 (a int, b int, index(a), index(b));
+create table t2 (c int auto_increment, d varchar(255), primary key (c));
+insert into t1 values (3,1),(3,2);
+insert into t2 values (NULL, 'foo'), (NULL, 'bar');
+select d, c from t1 left join t2 on b = c where a = 3 order by d;
+drop table t1, t2;

sql/ha_heap.cc

@@ -408,7 +408,8 @@ THR_LOCK_DATA **ha_heap::store_lock(THD *thd,
 int ha_heap::delete_table(const char *name)
 {
   char buff[FN_REFLEN];
-  int error= heap_delete_table(fn_format(buff,name,"","",4+2));
+  int error= heap_delete_table(fn_format(buff,name,"","",
+                                         MY_REPLACE_EXT|MY_UNPACK_FILENAME));
   return error == ENOENT ? 0 : error;
 }
 
@@ -521,7 +522,8 @@ int ha_heap::create(const char *name, TABLE *table_arg,
 				  create_info->auto_increment_value - 1 : 0);
   hp_create_info.max_table_size=current_thd->variables.max_heap_table_size;
   max_rows = (ha_rows) (hp_create_info.max_table_size / mem_per_row);
-  error= heap_create(fn_format(buff,name,"","",4+2),
+  error= heap_create(fn_format(buff,name,"","",
+                               MY_REPLACE_EXT|MY_UNPACK_FILENAME),
 		     table_arg->keys,keydef, table_arg->reclength,
 		     (ulong) ((table_arg->max_rows < max_rows &&
 			       table_arg->max_rows) ?

sql/sql_select.cc

@@ -4880,12 +4880,14 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
     temp_pool_slot = bitmap_set_next(&temp_pool);
 
   if (temp_pool_slot != MY_BIT_NONE) // we got a slot
-    sprintf(path, "%s%s_%lx_%i", mysql_tmpdir, tmp_file_prefix,
+    sprintf(path, "%s_%lx_%i", tmp_file_prefix,
 	    current_pid, temp_pool_slot);
   else // if we run out of slots or we are not using tempool
-    sprintf(path,"%s%s%lx_%lx_%x",mysql_tmpdir,tmp_file_prefix,current_pid,
+    sprintf(path,"%s%lx_%lx_%x", tmp_file_prefix,current_pid,
             thd->thread_id, thd->tmp_table++);
 
+  fn_format(path, path, mysql_tmpdir, "", MY_REPLACE_EXT|MY_UNPACK_FILENAME);
+
   if (lower_case_table_names)
     my_casedn_str(files_charset_info, path);