honor the enabled=false flag at the top-level of doc mapping

fixes #331

mapping_index.go

@@ -402,6 +402,7 @@ func (im *IndexMapping) mapDocument(doc *document.Document, data interface{}) er
 	docType := im.determineType(data)
 	docMapping := im.mappingForType(docType)
 	walkContext := im.newWalkContext(doc, docMapping)
+	if docMapping.Enabled {
 		docMapping.walkDocument(data, []string{}, []uint64{}, walkContext)
 
 		// see if the _all field was disabled
@@ -410,6 +411,7 @@ func (im *IndexMapping) mapDocument(doc *document.Document, data interface{}) er
 			field := document.NewCompositeFieldWithIndexingOptions("_all", true, []string{}, walkContext.excludedFromAll, document.IndexField|document.IncludeTermVectors)
 			doc.AddField(field)
 		}
+	}
 
 	return nil
 }

mapping_test.go

@@ -402,3 +402,22 @@ func TestMappingBool(t *testing.T) {
 		t.Errorf("expected to find 2 fields, found %d", count)
 	}
 }
+
+func TestDisableDefaultMapping(t *testing.T) {
+	indexMapping := NewIndexMapping()
+	indexMapping.DefaultMapping.Enabled = false
+
+	data := map[string]string{
+		"name": "bleve",
+	}
+
+	doc := document.NewDocument("x")
+	err := indexMapping.mapDocument(doc, data)
+	if err != nil {
+		t.Error(err)
+	}
+
+	if len(doc.Fields) > 0 {
+		t.Errorf("expected no fields, got %d", len(doc.Fields))
+	}
+}