prevent jmoiron#49 from happening by returning an error when a nil sl…

…ice ptr or nil struct ptr has been passed to Select and Get

sqlx.go

@@ -813,6 +813,9 @@ func (r *Row) StructScan(dest interface{}) error {
 	if v.Kind() != reflect.Ptr {
 		return errors.New("must pass a pointer, not a value, to StructScan destination")
 	}
+	if v.IsNil() {
+		return errors.New("nil pointer passed to StructScan destination")
+	}
 
 	direct := reflect.Indirect(v)
 	base, err := BaseStructType(direct.Type())
@@ -938,6 +941,9 @@ func StructScan(rows rowsi, dest interface{}) error {
 	if value.Kind() != reflect.Ptr {
 		return errors.New("must pass a pointer, not a value, to StructScan destination")
 	}
+	if value.IsNil() {
+		return errors.New("nil pointer passed to StructScan destination")
+	}
 
 	direct := reflect.Indirect(value)
 

sqlx_test.go

@@ -430,6 +430,22 @@ func TestEmbeddedStructs(t *testing.T) {
 	})
 }
 
+func TestNilReceiver(t *testing.T) {
+	RunWithSchema(defaultSchema, t, func(db *DB, t *testing.T) {
+		loadDefaultFixture(db, t)
+		var p *Person
+		err := db.Get(p, "SELECT * FROM person LIMIT 1")
+		if err == nil {
+			t.Error("Expected error when getting into nil struct ptr.")
+		}
+		var pp *[]Person
+		err = db.Select(pp, "SELECT * FROM person")
+		if err == nil {
+			t.Error("Expected an error when selecting into nil slice ptr.")
+		}
+	})
+}
+
 func TestNamedQuery(t *testing.T) {
 	var schema = Schema{
 		create: `