From 5602e75a5081541e98bc583754592c90d2442446 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Furga=C5=82a?=
 <83299832+00200200@users.noreply.github.com>
Date: Tue, 29 Sep 2026 17:32:37 +0200
Subject: [PATCH] upload: add trailing slash to /legacy repository URLs

Warehouse treats /legacy and /legacy/ as different resources, so a
.pypirc entry of https://test.pypi.org/legacy does not accept uploads.
---
 flit/upload.py       | 18 ++++++++++++++++--
 tests/test_upload.py | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/flit/upload.py b/flit/upload.py
index 79c117dd..31a5c6ec 100644
--- a/flit/upload.py
+++ b/flit/upload.py
@@ -14,7 +14,7 @@
 import sys
 from dataclasses import dataclass
 from typing import Optional
-from urllib.parse import urlparse
+from urllib.parse import urlparse, urlunparse
 
 from flit_core.common import make_metadata, Metadata, Module
 from .config import read_flit_config
@@ -44,6 +44,19 @@ def is_pypi(self):
         return self.url.rstrip('/').endswith('/legacy')
 
 
+def normalize_repository_url(url: str) -> str:
+    """Ensure Warehouse's ``/legacy`` upload API has a trailing slash.
+
+    ``https://test.pypi.org/legacy`` (no slash) is a different resource from
+    ``.../legacy/`` and does not accept uploads (issue #179).
+    """
+    parsed = urlparse(url)
+    path = parsed.path or ''
+    if path.rstrip('/') == '/legacy' and not path.endswith('/'):
+        return urlunparse(parsed._replace(path=path + '/'))
+    return url
+
+
 def get_repositories(file="~/.pypirc"):
     """Get the known repositories from a pypirc file.
 
@@ -278,7 +291,8 @@ def upload_file(file:Path, metadata:Metadata, repo: RepoDetails):
 
     log.info('Uploading %s...', file)
     resp = requests.post(
-        repo.url, data=data, files=files, auth=(repo.username, repo.password),
+        normalize_repository_url(repo.url), data=data, files=files,
+        auth=(repo.username, repo.password),
     )
     resp.raise_for_status()
 
diff --git a/tests/test_upload.py b/tests/test_upload.py
index 95b13a01..44eb3fa9 100644
--- a/tests/test_upload.py
+++ b/tests/test_upload.py
@@ -143,6 +143,45 @@ def test_upload_pypirc_file(copy_sample):
         assert repo.password == pypirc3_pass
 
 
+@responses.activate
+def test_upload_legacy_url_without_trailing_slash(copy_sample):
+    # Warehouse's /legacy upload API requires a trailing slash. Without it the
+    # request hits a different resource (404 historically, 405 today). See #179.
+    repo = RepoDetails(
+        url="https://test.pypi.org/legacy",
+        username="user",
+        password="pw",
+    )
+    responses.add(responses.POST, "https://test.pypi.org/legacy/", status=200)
+    td = copy_sample("module1_toml")
+
+    with temp_pypirc(pypirc1) as pypirc, patch(
+        "flit.upload.get_repository", return_value=repo
+    ):
+        upload.main(td / "pyproject.toml", repo_name="pypi", pypirc_path=pypirc)
+
+    assert len(responses.calls) == 2
+    for call in responses.calls:
+        assert call.request.url == "https://test.pypi.org/legacy/"
+
+
+def test_normalize_repository_url():
+    assert (
+        upload.normalize_repository_url("https://test.pypi.org/legacy")
+        == "https://test.pypi.org/legacy/"
+    )
+    assert (
+        upload.normalize_repository_url("https://upload.pypi.org/legacy")
+        == "https://upload.pypi.org/legacy/"
+    )
+    already = "https://upload.pypi.org/legacy/"
+    assert upload.normalize_repository_url(already) == already
+    other = "https://pypi.example.com"
+    assert upload.normalize_repository_url(other) == other
+    with_query = "https://test.pypi.org/legacy?foo=1"
+    assert upload.normalize_repository_url(with_query) == "https://test.pypi.org/legacy/?foo=1"
+
+
 def test_upload_invalid_pypirc_file(copy_sample):
     with patch("flit.upload.upload_file"):
         td = copy_sample("module1_toml")