Fix miscellaneous prod bugs.

service/datastore/pls.go

Index: service/datastore/pls.go
diff --git a/service/datastore/pls.go b/service/datastore/pls.go
index 35eb42dc3c03a94be6313915ea5ed85f40b631b7..6b9b7766b138ad126281b0e729b9065de66ec14b 100644
--- a/service/datastore/pls.go
+++ b/service/datastore/pls.go
@@ -24,11 +24,11 @@ import (
 //
 // GetPLS supports the following struct tag syntax:
 //   `gae:"fieldName[,noindex]"` -- an alternate fieldname for an exportable
-//	    field.  When the struct is serialized or deserialized, fieldName will be
+//      field.  When the struct is serialized or deserialized, fieldName will be
 //      associated with the struct field instead of the field's Go name. This is
 //      useful when writing Go code which interfaces with appengine code written
 //      in other languages (like python) which use lowercase as their default
-//		  datastore field names.
+//      datastore field names.
 //
 //      A fieldName of "-" means that gae will ignore the field for all
 //      serialization/deserialization.
@@ -87,16 +87,23 @@ import (
 //     Lines []string
 //   }
 func GetPLS(obj interface{}) PropertyLoadSaver {
+	v, err := getPLSValue(obj)
+	if err != nil {
+		return &structPLS{c: &structCodec{problem: err}}
+	}
+	c := getCodec(v.Type())
+	return &structPLS{v, c}
+}
+
+func getPLSValue(obj interface{}) (reflect.Value, error) {
 	v := reflect.ValueOf(obj)
 	if v.Kind() != reflect.Ptr || v.Elem().Kind() != reflect.Struct {
-		return &structPLS{c: &structCodec{problem: ErrInvalidEntityType}}
+		return reflect.Value{}, ErrInvalidEntityType
 	}
 	if v.IsNil() {
-		return &structPLS{c: &structCodec{problem: ErrInvalidEntityType}}
+		return reflect.Value{}, ErrInvalidEntityType
 	}
-	v = v.Elem()
-	c := getCodec(v.Type())
-	return &structPLS{v, c}
+	return v.Elem(), nil
 }
 
 func getCodec(structType reflect.Type) *structCodec {