diff --git a/mysql-test/lib/v1/mysql-test-run.pl b/mysql-test/lib/v1/mysql-test-run.pl
index 5d06d9c4dd8..c230897c502 100755
--- a/mysql-test/lib/v1/mysql-test-run.pl
+++ b/mysql-test/lib/v1/mysql-test-run.pl
@@ -5204,8 +5204,8 @@ sub valgrind_arguments {
   else
   {
     mtr_add_arg($args, "--tool=memcheck"); # From >= 2.1.2 needs this option
-    mtr_add_arg($args, "--alignment=8");
     mtr_add_arg($args, "--leak-check=yes");
+    #mtr_add_arg($args, "--db-attach=yes");
     mtr_add_arg($args, "--num-callers=16");
     mtr_add_arg($args, "--suppressions=%s/valgrind.supp", $glob_mysql_test_dir)
       if -f "$glob_mysql_test_dir/valgrind.supp";
diff --git a/mysql-test/r/func_time.result b/mysql-test/r/func_time.result
index 654ab0f7351..781d2bf3e97 100644
--- a/mysql-test/r/func_time.result
+++ b/mysql-test/r/func_time.result
@@ -812,7 +812,7 @@ create table t1 select last_day('2000-02-05') as a,
 from_days(to_days("960101")) as b;
 describe t1;
 Field	Type	Null	Key	Default	Extra
-a	date	NO		0000-00-00	
+a	date	YES		NULL	
 b	date	YES		NULL	
 select * from t1;
 a	b
@@ -1442,3 +1442,29 @@ drop table t1;
 select maketime(20,61,10)+0;
 maketime(20,61,10)+0
 NULL
+create table t1 (f2 int not null) ;
+insert into t1 values (0),(0);
+select last_day(f2) from t1;
+last_day(f2)
+NULL
+NULL
+Warnings:
+Warning	1292	Incorrect datetime value: '0'
+Warning	1292	Incorrect datetime value: '0'
+select last_day(f2) from t1 where last_day(f2) is null;
+last_day(f2)
+NULL
+NULL
+Warnings:
+Warning	1292	Incorrect datetime value: '0'
+Warning	1292	Incorrect datetime value: '0'
+Warning	1292	Incorrect datetime value: '0'
+Warning	1292	Incorrect datetime value: '0'
+select * from t1 order by last_day (f2);
+f2
+0
+0
+Warnings:
+Warning	1292	Incorrect datetime value: '0'
+Warning	1292	Incorrect datetime value: '0'
+drop table t1;
diff --git a/mysql-test/t/func_time.test b/mysql-test/t/func_time.test
index a24261cdf90..5d8d4427ab0 100644
--- a/mysql-test/t/func_time.test
+++ b/mysql-test/t/func_time.test
@@ -901,3 +901,12 @@ drop table t1;
 #
 select maketime(20,61,10)+0;
 
+#
+# lp:731103 Assertion `maybe_null && item->null_value' failed with ORDER BY LAST_DAY()
+#
+create table t1 (f2 int not null) ;
+insert into t1 values (0),(0);
+select last_day(f2) from t1;
+select last_day(f2) from t1 where last_day(f2) is null;
+select * from t1 order by last_day (f2);
+drop table t1;
diff --git a/sql/item_timefunc.h b/sql/item_timefunc.h
index e2e65142902..36be86cd89c 100644
--- a/sql/item_timefunc.h
+++ b/sql/item_timefunc.h
@@ -862,4 +862,9 @@ public:
   Item_func_last_day(Item *a) :Item_datefunc(a) {}
   const char *func_name() const { return "last_day"; }
   bool get_date(MYSQL_TIME *res, uint fuzzy_date);
+  void fix_length_and_dec()
+  { 
+    maybe_null=1;
+    Item_datefunc::fix_length_and_dec();
+  }
 };