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, 19 insertions, 0 deletions

diff --git a/mysql-test/t/user_var.test b/mysql-test/t/user_var.test
index 4f27866de23..efaf8afd91e 100644
--- a/mysql-test/t/user_var.test
+++ b/mysql-test/t/user_var.test
@@ -346,4 +346,23 @@ FROM t1 GROUP BY a LIMIT 1;
 
 DROP TABLE t1;
 
+#
+# BUG#56138 "valgrind errors about overlapping memory when
+# double-assigning same variable"
+#
+
+select @v:=@v:=sum(1) from dual;
+
+#
+# Bug #57187: more user variable fun with multiple assignments and
+#             comparison in query
+#
+
+CREATE TABLE t1(a DECIMAL(31,21));
+INSERT INTO t1 VALUES (0);
+
+SELECT (@v:=a) <> (@v:=1) FROM t1;
+
+DROP TABLE t1;
+
 --echo End of 5.1 tests