Fix #1642: Don't flag download as interrupted when Content-Encoding is set

httpie/downloads.py

@@ -216,12 +216,21 @@ def start(
         """
         assert not self.status.time_started
 
-        # FIXME: some servers still might sent Content-Encoding: gzip
-        # <https://github.com/httpie/cli/issues/423>
-        try:
-            total_size = int(final_response.headers['Content-Length'])
-        except (KeyError, ValueError, TypeError):
+        # When Content-Encoding is set (e.g. gzip), the requests library
+        # transparently decompresses the response body. This means the
+        # actual bytes written will differ from Content-Length (which
+        # reflects the compressed size). In this case, we cannot rely
+        # on Content-Length for progress/completeness tracking.
+        # See: https://github.com/httpie/cli/issues/423
+        # See: https://github.com/httpie/cli/issues/1642
+        content_encoding = final_response.headers.get('Content-Encoding')
+        if content_encoding:
             total_size = None
+        else:
+            try:
+                total_size = int(final_response.headers['Content-Length'])
+            except (KeyError, ValueError, TypeError):
+                total_size = None
 
         if not self._output_file:
             self._output_file = self._get_output_file_from_response(

tests/test_downloads.py

@@ -247,6 +247,36 @@ def test_download_resumed(self, mock_env, httpbin_both):
                 downloader.chunk_downloaded(b'45')
                 downloader.finish()
 
+    def test_download_with_Content_Encoding_gzip_not_interrupted(self, mock_env, httpbin_both):
+        """
+        When Content-Encoding is set (e.g. gzip), the requests library
+        transparently decompresses the body, so the downloaded bytes
+        will differ from Content-Length (which is the compressed size).
+        httpie should NOT flag this as an interrupted download.
+
+        Regression test for https://github.com/httpie/cli/issues/1642
+        """
+        with open(os.devnull, 'w') as devnull:
+            downloader = Downloader(mock_env, output_file=devnull)
+            # Simulate a gzip-encoded response where Content-Length is
+            # the compressed size (100 bytes) but the decompressed body
+            # is larger (500 bytes).
+            downloader.start(
+                initial_url='/',
+                final_response=Response(
+                    url=httpbin_both.url + '/',
+                    headers={
+                        'Content-Length': 100,
+                        'Content-Encoding': 'gzip',
+                    }
+                )
+            )
+            # Simulate receiving decompressed data (larger than Content-Length)
+            downloader.chunk_downloaded(b'x' * 500)
+            downloader.finish()
+            # Should NOT be flagged as interrupted
+            assert not downloader.interrupted
+
     def test_download_with_redirect_original_url_used_for_filename(self, httpbin):
         # Redirect from `/redirect/1` to `/get`.
         expected_filename = '1.json'