Proposed bugfix for #712

Monty revoked any locks for temporary tables in
ha_myisam::external_lock()
But further code bans using write cache on nonlocked tables
this makes operations much slower


myisam/mi_locking.c:
  Handling of MI_TEMPORARY_TABLE lock
myisam/myisamdef.h:
  defining of MI_TEMPORARY_TABLE
sql/ha_myisam.cc:
  now we lock temporary tables using MI_TEMPORARY_TABLE lock

1 files changed, 5 insertions, 4 deletions

diff --git a/sql/ha_myisam.cc b/sql/ha_myisam.cc
index 595123f7ac1..969fa3232c3 100644
--- a/sql/ha_myisam.cc
+++ b/sql/ha_myisam.cc
@@ -559,7 +559,8 @@ int ha_myisam::repair(THD *thd, MI_CHECK &param, bool optimize)
   strmov(fixed_name,file->filename);
 
   // Don't lock tables if we have used LOCK TABLE
-  if (!thd->locked_tables && mi_lock_database(file,F_WRLCK))
+  if (!thd->locked_tables && 
+      mi_lock_database(file, table->tmp_table ? MI_TEMPORARY_TABLE : F_WRLCK))
   {
     mi_check_print_error(&param,ER(ER_CANT_LOCK),my_errno);
     DBUG_RETURN(HA_ADMIN_FAILED);
@@ -999,9 +1000,9 @@ int ha_myisam::delete_table(const char *name)
 
 int ha_myisam::external_lock(THD *thd, int lock_type)
 {
-  if (!table->tmp_table)
-    return mi_lock_database(file,lock_type);
-  return 0;
+  return mi_lock_database(file, !table->tmp_table ?
+			  lock_type : ((lock_type == F_UNLCK) ?
+				       F_UNLCK : MI_TEMPORARY_TABLE));
 }