Merge rkalimullin@bk-internal.mysql.com:/home/bk/mysql-5.0-maint

into  mysql.com:/usr/home/ram/work/bug21587/my50-bug21587

sql/mysql_priv.h

@@ -941,6 +941,7 @@ bool mysql_ha_read(THD *, TABLE_LIST *,enum enum_ha_read_modes,char *,
                    List<Item> *,enum ha_rkey_function,Item *,ha_rows,ha_rows);
 int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags,
                    bool is_locked);
+void mysql_ha_mark_tables_for_reopen(THD *thd, TABLE *table);
 /* mysql_ha_flush mode_flags bits */
 #define MYSQL_HA_CLOSE_FINAL        0x00
 #define MYSQL_HA_REOPEN_ON_USAGE    0x01

sql/sql_base.cc

@@ -519,7 +519,15 @@ void close_thread_tables(THD *thd, bool lock_in_use, bool skip_derived)
 
   DBUG_PRINT("info", ("thd->open_tables: %p", thd->open_tables));
 
- found_old_table= 0;
+  
+  /* 
+    End open index scans and table scans and remove references to the tables 
+    from the handler tables hash. After this preparation it is safe to close 
+    the tables.
+  */
+  mysql_ha_mark_tables_for_reopen(thd, thd->open_tables);
+
+  found_old_table= 0;
   while (thd->open_tables)
     found_old_table|=close_thread_table(thd, &thd->open_tables);
   thd->some_tables_deleted=0;

sql/sql_handler.cc

@@ -748,3 +748,41 @@ static int mysql_ha_flush_table(THD *thd, TABLE **table_ptr, uint mode_flags)
 
   DBUG_RETURN(0);
 }
+
+
+/*
+  Mark tables for reopen.
+
+  SYNOPSIS
+    mysql_ha_mark_tables_for_reopen()
+    thd                         Thread identifier.
+    table                       Table list to mark for reopen.
+
+  DESCRIPTION
+    For each table found in the handler hash mark it as closed
+    (ready for reopen) and end all index/table scans.
+
+  NOTE
+    The caller must lock LOCK_open.
+*/
+
+void mysql_ha_mark_tables_for_reopen(THD *thd, TABLE *table)
+{
+  DBUG_ENTER("mysql_ha_mark_tables_for_reopen");
+
+  safe_mutex_assert_owner(&LOCK_open);
+  for (; table; table= table->next)
+  {
+    TABLE_LIST *hash_tables;
+    if ((hash_tables= (TABLE_LIST*) hash_search(&thd->handler_tables_hash,
+                                                (byte*) table->alias,
+                                                strlen(table->alias) + 1)))
+    {
+      /* Mark table as ready for reopen. */
+      hash_tables->table= NULL;
+      /* End open index/table scans. */
+      table->file->ha_index_or_rnd_end();
+    }
+  }
+  DBUG_VOID_RETURN;
+}