Handle orientation of zero as no orientation

CHANGELOG.md

@@ -12,6 +12,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 * Added a new tool, `export_synapse_for_import`, which can be used to do an offline import from Synapse.
   * After running this tool, use the `gdpr_import` tool to bring the export into the media repo.
 
+### Fixed
+
+* Fixed thumbnails for invalid JPEGs.
+
 ## [1.2.0] - August 2nd, 2020
 
 ### Upgrade notes

util/util_exif/exif.go

@@ -40,6 +40,11 @@ func GetExifOrientation(img io.ReadCloser) (*ExifOrientation, error) {
 		return nil, errors.New("exif: error parsing orientation: " + err.Error())
 	}
 
+	// Some devices produce invalid exif data when they intend to mean "no orientation"
+	if orientation == 0 {
+		return nil, nil
+	}
+
 	if orientation < 1 || orientation > 8 {
 		return nil, errors.New(fmt.Sprintf("orientation out of range: %d", orientation))
 	}