From 9a72f42f8871604c1ca5c120bad8aff7e7f23aa2 Mon Sep 17 00:00:00 2001
From: Olzhas Arystanov <olzhas.arystanov@reef.pl>
Date: Tue, 16 Dec 2025 03:01:39 +0500
Subject: [PATCH] Avoid http-level retries during upload requests

This PR fixes the b2http logic to avoid any retries during the upload
requests. Previously, the http layer would still proceed with retries
during upload failures, preventing the upload manager from issuing a new
upload token.
There was a workaround only for timeout errors, but it didn't quite work as
expected.
---
 b2sdk/_internal/b2http.py                     | 31 ++++++++++++-------
 .../+b2http-upload-no-retries.fixed.md        |  1 +
 test/unit/b2http/test_b2http.py               | 31 +++++++++++++++++++
 3 files changed, 52 insertions(+), 11 deletions(-)
 create mode 100644 changelog.d/+b2http-upload-no-retries.fixed.md

diff --git a/b2sdk/_internal/b2http.py b/b2sdk/_internal/b2http.py
index 2f0df66a..6715ef85 100644
--- a/b2sdk/_internal/b2http.py
+++ b/b2sdk/_internal/b2http.py
@@ -36,12 +36,12 @@
     B2ConnectionError,
     B2Error,
     B2RequestTimeout,
-    B2RequestTimeoutDuringUpload,
     BadDateFormat,
     BrokenPipe,
     ClockSkew,
     ConnectionReset,
     PotentialS3EndpointPassedAsRealm,
+    ServiceError,
     UnknownError,
     UnknownHost,
     interpret_b2_error,
@@ -281,7 +281,7 @@ def do_request():
             self._run_post_request_hooks(method, url, request_headers, response)
             return response
 
-        return self._translate_and_retry(do_request, try_count, params)
+        return self._translate_and_retry(do_request, try_count, method, request_headers, params)
 
     def request_content_return_json(
         self,
@@ -355,14 +355,9 @@ def post_content_return_json(
         :param data: a file-like object to send
         :return: a dict that is the decoded JSON
         """
-        try:
-            return self.request_content_return_json(
-                'POST', url, headers, data, try_count, post_params, _timeout=_timeout
-            )
-        except B2RequestTimeout:
-            # this forces a token refresh, which is necessary if request is still alive
-            # on the server but has terminated for some reason on the client. See #79
-            raise B2RequestTimeoutDuringUpload()
+        return self.request_content_return_json(
+            'POST', url, headers, data, try_count, post_params, _timeout=_timeout
+        )
 
     def post_json_return_json(self, url, headers, params, try_count: int = TRY_COUNT_OTHER):
         """
@@ -579,7 +574,12 @@ def _translate_errors(cls, fcn, post_params=None):
 
     @classmethod
     def _translate_and_retry(
-        cls, fcn: Callable, try_count: int, post_params: dict[str, Any] | None = None
+        cls,
+        fcn: Callable,
+        try_count: int,
+        method: str,
+        headers: dict[str, Any],
+        post_params: dict[str, Any] | None = None,
     ):
         """
         Try calling fcn try_count times, retrying only if
@@ -598,6 +598,15 @@ def _translate_and_retry(
             except B2Error as e:
                 if not e.should_retry_http():
                     raise
+                if (
+                    method == 'POST'
+                    and 'X-Bz-Content-Sha1' in headers
+                    and isinstance(e, (ServiceError, B2RequestTimeout))
+                ):
+                    # This is an upload operation, so we avoid http-level retries
+                    # here to force an upload token refresh
+                    raise
+
                 logger.debug(str(e), exc_info=True)
                 if e.retry_after_seconds is not None:
                     sleep_duration = e.retry_after_seconds
diff --git a/changelog.d/+b2http-upload-no-retries.fixed.md b/changelog.d/+b2http-upload-no-retries.fixed.md
new file mode 100644
index 00000000..7dbbfcd5
--- /dev/null
+++ b/changelog.d/+b2http-upload-no-retries.fixed.md
@@ -0,0 +1 @@
+Avoid http-level retries during upload requests.
\ No newline at end of file
diff --git a/test/unit/b2http/test_b2http.py b/test/unit/b2http/test_b2http.py
index ae91e6bf..a8761a9d 100644
--- a/test/unit/b2http/test_b2http.py
+++ b/test/unit/b2http/test_b2http.py
@@ -387,6 +387,37 @@ def test_too_many_requests_retry_header_combination_two(
         b2_http.request(responses.GET, self.URL, {}, try_count=4)
         assert mock_time.mock_calls == [call(1.0), call(5), call(2.25)]
 
+    @responses.activate
+    def test_service_error_during_upload_no_retries(self, b2_http: B2Http, mock_time: MagicMock):
+        _mock_error_response(self.URL, method=responses.POST, status=503)
+        responses.post(self.URL)
+
+        headers = {'X-Bz-Content-Sha1': '1234'}
+
+        with pytest.raises(ServiceError):
+            b2_http.request(responses.POST, self.URL, headers)
+
+        mock_time.assert_not_called()
+
+    @responses.activate
+    def test_request_timeout_during_upload_no_retries(self, b2_http: B2Http, mock_time: MagicMock):
+        responses.post(
+            self.URL,
+            body=requests.ConnectionError(
+                requests.packages.urllib3.exceptions.ProtocolError(
+                    'dummy', TimeoutError('The write operation timed out')
+                )
+            ),
+        )
+        responses.post(self.URL)
+
+        headers = {'X-Bz-Content-Sha1': '1234'}
+
+        with pytest.raises(B2RequestTimeout):
+            b2_http.request(responses.POST, self.URL, headers)
+
+        mock_time.assert_not_called()
+
 
 class TestB2Http:
     URL = 'http://example.com'