fix(pip): preserve PEP 508 URL-based requirements when extract_url_srcs=False (#3582)

pip_parse (via pip_repository) passes extract_url_srcs=False to
parse_requirements. The _package_srcs() function silently dropped PEP
508 URL-based requirements (pkg @ https://...) in this mode because
_add_dists() returns can_fallback=False for URL requirements, causing
them to fall through to the `continue` statement.

Fix the elif condition to also accept the case where extract_url_srcs is
False but a valid URL dist exists, falling back to pip to handle the URL
requirement directly.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
(cherry picked from commit 9dcbabb3fafe847291850ff9a249e46f6fca5ef4)

CHANGELOG.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f397c82..81ca109 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -57,6 +57,9 @@
 ### Fixed
 * (runfiles) Fixed `CurrentRepository()` raising `ValueError` on Windows.
   ([#3579](https://github.com/bazel-contrib/rules_python/issues/3579))
+* (pypi) `pip_parse` no longer silently drops PEP 508 URL-based requirements
+  (`pkg @ https://...`) when `extract_url_srcs=False` (the default for
+  `pip_repository`).
 
 {#v1-8-4}
 ## [1.8.4] - 2026-02-10

python/private/pypi/parse_requirements.bzl

diff --git a/python/private/pypi/parse_requirements.bzl b/python/private/pypi/parse_requirements.bzl
index 5c05c75..760bf5a 100644
--- a/python/private/pypi/parse_requirements.bzl
+++ b/python/private/pypi/parse_requirements.bzl
@@ -260,7 +260,7 @@
 
             if extract_url_srcs and dist:
                 req_line = r.srcs.requirement
-            elif can_fallback:
+            elif can_fallback or (not extract_url_srcs and dist):
                 dist = struct(
                     url = "",
                     filename = "",

tests/pypi/parse_requirements/parse_requirements_tests.bzl

diff --git a/tests/pypi/parse_requirements/parse_requirements_tests.bzl b/tests/pypi/parse_requirements/parse_requirements_tests.bzl
index 63755d2..a2efe91 100644
--- a/tests/pypi/parse_requirements/parse_requirements_tests.bzl
+++ b/tests/pypi/parse_requirements/parse_requirements_tests.bzl
@@ -192,6 +192,47 @@
 
 _tests.append(_test_direct_urls_integration)
 
+def _test_direct_urls_no_extract(env):
+    """Check that URL requirements are not dropped when extract_url_srcs=False."""
+    got = parse_requirements(
+        requirements_by_platform = {
+            "requirements_direct": ["linux_x86_64"],
+            "requirements_direct_sdist": ["osx_x86_64"],
+        },
+        extract_url_srcs = False,
+    )
+    env.expect.that_collection(got).contains_exactly([
+        struct(
+            name = "foo",
+            is_exposed = True,
+            is_multiple_versions = True,
+            srcs = [
+                struct(
+                    distribution = "foo",
+                    extra_pip_args = [],
+                    filename = "",
+                    requirement_line = "foo @ https://github.com/org/foo/downloads/foo-1.1.tar.gz",
+                    sha256 = "",
+                    target_platforms = ["osx_x86_64"],
+                    url = "",
+                    yanked = False,
+                ),
+                struct(
+                    distribution = "foo",
+                    extra_pip_args = [],
+                    filename = "",
+                    requirement_line = "foo[extra] @ https://some-url/package.whl",
+                    sha256 = "",
+                    target_platforms = ["linux_x86_64"],
+                    url = "",
+                    yanked = False,
+                ),
+            ],
+        ),
+    ])
+
+_tests.append(_test_direct_urls_no_extract)
+
 def _test_extra_pip_args(env):
     got = parse_requirements(
         requirements_by_platform = {