fixes

src/pip/_internal/req/constructors.py

@@ -8,10 +8,11 @@ These are meant to be used elsewhere within pip to create instances of
 InstallRequirement.
 """
 
+import copy
 import logging
 import os
 import re
-from typing import Dict, List, Optional, Set, Tuple, Union
+from typing import Collection, Dict, List, Optional, Set, Tuple, Union
 
 from pip._vendor.packaging.markers import Marker
 from pip._vendor.packaging.requirements import InvalidRequirement, Requirement
@@ -512,7 +513,6 @@ def install_req_without(
     without_extras: bool = False,
     without_specifier: bool = False,
 ) -> InstallRequirement:
-    # TODO: clean up hack
     req = Requirement(str(ireq.req))
     if without_extras:
         req.extras = {}
@@ -535,3 +535,19 @@ def install_req_without(
         user_supplied=ireq.user_supplied,
         permit_editable_wheels=ireq.permit_editable_wheels,
     )
+
+
+def install_req_extend_extras(
+    ireq: InstallRequirement,
+    extras: Collection[str],
+) -> InstallRequirement:
+    """
+    Returns a copy of an installation requirement with some additional extras.
+    Makes a shallow copy of the ireq object.
+    """
+    result = copy.copy(ireq)
+    req = Requirement(str(ireq.req))
+    req.extras.update(extras)
+    result.req = req
+    result.extras = {*ireq.extras, *extras}
+    return result

src/pip/_internal/resolution/resolvelib/resolver.py

@@ -1,3 +1,4 @@
+import contextlib
 import functools
 import logging
 import os
@@ -11,6 +12,7 @@ from pip._vendor.resolvelib.structs import DirectedGraph
 from pip._internal.cache import WheelCache
 from pip._internal.index.package_finder import PackageFinder
 from pip._internal.operations.prepare import RequirementPreparer
+from pip._internal.req.constructors import install_req_extend_extras
 from pip._internal.req.req_install import InstallRequirement
 from pip._internal.req.req_set import RequirementSet
 from pip._internal.resolution.base import BaseResolver, InstallRequirementProvider
@@ -19,6 +21,7 @@ from pip._internal.resolution.resolvelib.reporter import (
     PipDebuggingReporter,
     PipReporter,
 )
+from pip._internal.utils.packaging import get_requirement
 
 from .base import Candidate, Requirement
 from .factory import Factory
@@ -101,9 +104,19 @@ class Resolver(BaseResolver):
             raise error from e
 
         req_set = RequirementSet(check_supported_wheels=check_supported_wheels)
-        for candidate in result.mapping.values():
+        # sort to ensure base candidates come before candidates with extras
+        for candidate in sorted(result.mapping.values(), key=lambda c: c.name):
             ireq = candidate.get_install_requirement()
             if ireq is None:
+                if candidate.name != candidate.project_name:
+                    # extend existing req's extras
+                    with contextlib.suppress(KeyError):
+                        req = req_set.get_requirement(candidate.project_name)
+                        req_set.add_named_requirement(
+                            install_req_extend_extras(
+                                req, get_requirement(candidate.name).extras
+                            )
+                        )
                 continue
 
             # Check if there is already an installation under the same name,

tests/functional/test_install.py

@@ -2465,6 +2465,6 @@ def test_install_pip_prints_req_chain_pypi(script: PipTestEnvironment) -> None:
     )
 
     assert (
-        f"Collecting python-openid "
-        f"(from Paste[openid]==1.7.5.1->-r {req_path} (line 1))" in result.stdout
-    )
+        "Collecting python-openid "
+        f"(from Paste[openid]->Paste[openid]==1.7.5.1->-r {req_path} (line 1))"
+    ) in result.stdout