diff --git a/include/sql_string.h b/include/sql_string.h
index 8da554bef1ad..8c7052138829 100644
--- a/include/sql_string.h
+++ b/include/sql_string.h
@@ -679,7 +679,8 @@ class String
     char *ret= static_cast<char*>(alloc_root(root, m_length + 1));
     if (ret != NULL)
     {
-      memcpy(ret, m_ptr, m_length);
+      if (m_length > 0)
+        memcpy(ret, m_ptr, m_length);
       ret[m_length]= 0;
     }
     return ret;
diff --git a/plugin/keyring/common/keyring_key.cc b/plugin/keyring/common/keyring_key.cc
index 96695dd02eaf..bbb64f593558 100644
--- a/plugin/keyring/common/keyring_key.cc
+++ b/plugin/keyring/common/keyring_key.cc
@@ -79,7 +79,8 @@ void Key::store_field_length(uchar *buffer, size_t *buffer_position, size_t leng
 
 void Key::store_field(uchar *buffer, size_t *buffer_position, const char *field, size_t field_length) const
 {
-  memcpy(buffer + *buffer_position, field, field_length);
+  if (field_length > 0)
+    memcpy(buffer + *buffer_position, field, field_length);
   *buffer_position+= field_length;
 }
 
diff --git a/unittest/gunit/gis_algos-t.cc b/unittest/gunit/gis_algos-t.cc
index 9c9e6a5fd1a9..8d53c59a8d83 100644
--- a/unittest/gunit/gis_algos-t.cc
+++ b/unittest/gunit/gis_algos-t.cc
@@ -66,7 +66,7 @@ void SetRingOrderTest::set_order_and_compare(const std::string &s1,
   wkt.set(s1.c_str(), s1.length(), latincc);
   wkt2.set(s2.c_str(), s2.length(), latincc);
 
-  Gis_polygon_ring *ringp= static_cast<Gis_polygon_ring *>
+  Gis_line_string *ringp= static_cast<Gis_line_string *>
     (geometry_from_text(wkt, &str, &buffer));
   DBUG_ASSERT(ringp->get_geotype() == Geometry::wkb_linestring);
   Gis_polygon_ring ring(ringp->get_ptr(),
@@ -74,7 +74,7 @@ void SetRingOrderTest::set_order_and_compare(const std::string &s1,
   EXPECT_EQ(ring.set_ring_order(want_ccw), false);
 
 
-  ringp= static_cast<Gis_polygon_ring *>(geometry_from_text(wkt2, &str2,
+  ringp= static_cast<Gis_line_string *>(geometry_from_text(wkt2, &str2,
                                                             &buffer2));
   DBUG_ASSERT(ringp->get_geotype() == Geometry::wkb_linestring);
   Gis_polygon_ring ring2(ringp->get_ptr(),
@@ -155,7 +155,7 @@ TEST_F(SetRingOrderTest, RingDegradedToPointTest)
   std::string s1("linestring(0 0, 0 0, 0 0, 0 0, 0 0)");
   wkt.set(s1.c_str(), s1.length(), latincc);
 
-  Gis_polygon_ring *ringp= static_cast<Gis_polygon_ring *>
+  Gis_line_string *ringp= static_cast<Gis_line_string *>
     (geometry_from_text(wkt, &str, &buffer));
   DBUG_ASSERT(ringp->get_geotype() == Geometry::wkb_linestring);
   Gis_polygon_ring ring(ringp->get_ptr(),