Fix image memory issue (#935)

* Return slim images from mutations
* Fix potential memory leaks

graphql/documents/mutations/image.graphql

@@ -16,7 +16,7 @@ mutation ImageUpdate(
                         performer_ids: $performer_ids,
                         tag_ids: $tag_ids
                       }) {
-      ...ImageData
+      ...SlimImageData
   }
 }
 
@@ -38,13 +38,13 @@ mutation BulkImageUpdate(
                         performer_ids: $performer_ids,
                         tag_ids: $tag_ids
                       }) {
-      ...ImageData
+      ...SlimImageData
   }
 }
 
 mutation ImagesUpdate($input : [ImageUpdateInput!]!) {
   imagesUpdate(input: $input) {
-    ...ImageData
+    ...SlimImageData
   }
 }
 

pkg/image/image.go

@@ -90,11 +90,15 @@ func openSourceImage(path string) (io.ReadCloser, error) {
 			return nil, err
 		}
 
+		// defer closing of zip to the calling function, unless an error
+		// is returned, in which case it should be closed immediately
+
 		// find the file matching the filename
 		for _, f := range r.File {
 			if f.Name == filename {
 				src, err := f.Open()
 				if err != nil {
+					r.Close()
 					return nil, err
 				}
 				return &imageReadCloser{
@@ -104,6 +108,7 @@ func openSourceImage(path string) (io.ReadCloser, error) {
 			}
 		}
 
+		r.Close()
 		return nil, fmt.Errorf("file with name '%s' not found in zip file '%s'", filename, zipFilename)
 	}
 

pkg/manager/image.go

@@ -67,6 +67,7 @@ func walkGalleryZip(path string, walkFunc func(file *zip.File) error) error {
 	if err != nil {
 		return err
 	}
+	defer readCloser.Close()
 
 	for _, file := range readCloser.File {
 		if file.FileInfo().IsDir() {