fix: send correct content-range header if requested byte range was tr…

…uncated (#622)

Previously, if the requested byte range was truncated, an invalid
content-range header was sent.

gcs/object.py

@@ -369,6 +369,8 @@ def _download_range(self, request, response_payload):
                 begin = int(m.group(1))
                 end = int(m.group(2)) + 1
                 response_payload = response_payload[begin:end]
+                # Ensure end is correct if the specified byte range was truncated.
+                end = begin + len(response_payload)
             m = re.match("bytes=([0-9]+)-$", range_header)
             if m:
                 begin = int(m.group(1))