Fix urlretrieve reporthook to report actual bytes read

Author: savannahostrowski

Lib/test/test_urllib.py

@@ -727,7 +727,7 @@ def hooktester(block_count, block_read_size, file_size, _report=report):
         self.assertEqual(report[0][2], 8193)
         self.assertEqual(report[0][1], 8192)
         self.assertEqual(report[1][1], 8192)
-        self.assertEqual(report[2][1], 8192)
+        self.assertEqual(report[2][1], 1)  # last block only reads 1 byte
 
 
 class urlretrieve_HttpTests(unittest.TestCase, FakeHTTPMixin):

Lib/urllib/request.py

@@ -242,7 +242,7 @@ def urlretrieve(url, filename=None, reporthook=None, data=None):
                 tfp.write(block)
                 blocknum += 1
                 if reporthook:
-                    reporthook(blocknum, bs, size)
+                    reporthook(blocknum, len(block), size)
 
     if size >= 0 and read < size:
         raise ContentTooShortError(