urlcache: Check for no response from server

Signed-off-by: Hector Martin <[email protected]>

Author: marcan

src/urlcache.py

@@ -112,6 +112,9 @@ def get_partial(self, off, size, bypass_cache=False):
                 logging.error(f"Response headers: {res.headers.as_string()}")
             raise
 
+        if not d:
+            raise Exception(f"Server returned no data for for {self.url_str} range {off}-{off+size-1}")
+
         self.spin = (self.spin + 1) % len(self.SPINNER)
         sys.stdout.write(f"\r{self.SPINNER[self.spin]} ")
         sys.stdout.flush()