diff --git a/mysql-test/r/gis.result b/mysql-test/r/gis.result
index 93216fe2003..dfe375fd694 100644
--- a/mysql-test/r/gis.result
+++ b/mysql-test/r/gis.result
@@ -665,3 +665,8 @@ ERROR 22003: Cannot get geometry object from data you send to the GEOMETRY field
 insert into t1 values (pointfromtext('point(1,1)'));
 ERROR 22003: Cannot get geometry object from data you send to the GEOMETRY field
 drop table t1;
+create table t1 (s1 geometry not null,s2 char(100));
+create trigger t1_bu before update on t1 for each row set new.s1 = null;
+insert into t1 values (null,null);
+ERROR 23000: Column 's1' cannot be null
+drop table t1;
diff --git a/mysql-test/t/gis.test b/mysql-test/t/gis.test
index 661616c0a6c..202042d0257 100644
--- a/mysql-test/t/gis.test
+++ b/mysql-test/t/gis.test
@@ -373,3 +373,13 @@ insert into t1 values (pointfromtext('point(1,1)'));
 drop table t1;
 
 # End of 4.1 tests
+
+#
+# Bug #12281 (Geometry: crash in trigger)
+#
+
+create table t1 (s1 geometry not null,s2 char(100));
+create trigger t1_bu before update on t1 for each row set new.s1 = null;
+--error 1048
+insert into t1 values (null,null);
+drop table t1;
diff --git a/sql/field.h b/sql/field.h
index 523cf444c30..2b67ed3f599 100644
--- a/sql/field.h
+++ b/sql/field.h
@@ -1204,6 +1204,7 @@ public:
   int  store(longlong nr);
   int  store_decimal(const my_decimal *);
   void get_key_image(char *buff,uint length,imagetype type);
+  uint size_of() const { return sizeof(*this); }
 };
 #endif /*HAVE_SPATIAL*/