Merge with MySQL 5.1.55

- Fixed some issues with partitions and connection_string, which also fixed lp:716890 "Pre- and post-recovery crash in Aria"
- Fixed wrong assert in Aria

Now need to merge with latest xtradb before pushing 

sql/ha_partition.cc:
  Ensure that m_ordered_rec_buffer is not freed before close.
sql/mysqld.cc:
  Changed to use opt_stack_trace instead of opt_pstack.
  Removed references to pstack
sql/partition_element.h:
  Ensure that connect_string is initialized
storage/maria/ma_key_recover.c:
  Fixed wrong assert

client/mysql.cc

@@ -1,5 +1,5 @@
 /* Copyright (C) 2000-2009 MySQL AB
-   Copyright 2000, 2010, Oracle and/or its affiliates. All rights reserved.
+   Copyright 2000, 2010, Oracle and/or its affiliates.
    Copyright 2000-2010 Monty Program Ab
 
    This program is free software; you can redistribute it and/or modify
@@ -1462,8 +1462,8 @@ static struct my_option my_long_options[] =
    &opt_sigint_ignore,  &opt_sigint_ignore, 0, GET_BOOL,
    NO_ARG, 0, 0, 0, 0, 0, 0},
   {"one-database", 'o',
-   "Only update the default database. This is useful for skipping updates "
-   "to other database in the update log.",
+   "Ignore statements except those that occur while the default "
+   "database is the one named at the command line.",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
 #ifdef USE_POPEN
   {"pager", OPT_PAGER,
@@ -2757,6 +2757,10 @@ static void get_current_db()
 {
   MYSQL_RES *res;
 
+  /* If one_database is set, current_db is not supposed to change. */
+  if (one_database)
+    return;
+
   my_free(current_db, MYF(MY_ALLOW_ZERO_PTR));
   current_db= NULL;
   /* In case of error below current_db will be NULL */