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

1 files changed, 13 insertions, 0 deletions

diff --git a/sql/sql_connect.cc b/sql/sql_connect.cc
index 4811ce3cb45..bc833afc839 100644
--- a/sql/sql_connect.cc
+++ b/sql/sql_connect.cc
@@ -902,6 +902,19 @@ static int check_connection(THD *thd)
     user_len-= 2;
   }
 
+  /*
+    Clip username to allowed length in characters (not bytes).  This is
+    mostly for backward compatibility.
+  */
+  {
+    CHARSET_INFO *cs= system_charset_info;
+    int           err;
+
+    user_len= (uint) cs->cset->well_formed_len(cs, user, user + user_len,
+                                               USERNAME_CHAR_LENGTH, &err);
+    user[user_len]= '\0';
+  }
+
   if (thd->main_security_ctx.user)
     x_free(thd->main_security_ctx.user);
   if (!(thd->main_security_ctx.user= my_strdup(user, MYF(MY_WME))))