From ffe553638c035292e17657cbacbfb48e189a9221 Mon Sep 17 00:00:00 2001
From: Paul Moore <p.f.moore@gmail.com>
Date: Thu, 19 Mar 2020 10:53:15 +0000
Subject: [PATCH] Address review requirements

---
 .../resolution/resolvelib/candidates.py        | 18 +++++++++++++++---
 .../resolution/resolvelib/provider.py          |  8 ++++++++
 .../resolution/resolvelib/requirements.py      |  1 +
 3 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/src/pip/_internal/resolution/resolvelib/candidates.py b/src/pip/_internal/resolution/resolvelib/candidates.py
index a8e1aa903..08eff0ddf 100644
--- a/src/pip/_internal/resolution/resolvelib/candidates.py
+++ b/src/pip/_internal/resolution/resolvelib/candidates.py
@@ -7,7 +7,7 @@ from pip._internal.utils.typing import MYPY_CHECK_RUNNING
 from .base import Candidate
 
 if MYPY_CHECK_RUNNING:
-    from typing import Dict, Optional, Sequence
+    from typing import Any, Dict, Optional, Sequence
 
     from pip._internal.models.link import Link
     from pip._internal.operations.prepare import RequirementPreparer
@@ -17,7 +17,6 @@ if MYPY_CHECK_RUNNING:
     from pip._vendor.pkg_resources import Distribution
 
 
-# Dummy to make lint pass
 _CANDIDATE_CACHE = {}  # type: Dict[Link, Candidate]
 
 
@@ -74,9 +73,21 @@ class LinkCandidate(Candidate):
         self._version = None  # type: Optional[_BaseVersion]
         self._dist = None  # type: Optional[Distribution]
 
+    def __eq__(self, other):
+        # type: (Any) -> bool
+        if isinstance(other, self.__class__):
+            return self.link == other.link
+        return False
+
+    # Needed for Python 2, which does not implement this by default
+    def __ne__(self, other):
+        # type: (Any) -> bool
+        return not self.__eq__(other)
+
     @property
     def name(self):
         # type: () -> str
+        """The normalised name of the project the candidate refers to"""
         if self._name is None:
             self._name = canonicalize_name(self.dist.project_name)
         return self._name
@@ -101,7 +112,8 @@ class LinkCandidate(Candidate):
             # These should be "proper" errors, not just asserts, as they
             # can result from user errors like a requirement "foo @ URL"
             # when the project at URL has a name of "bar" in its metadata.
-            assert self._name is None or self._name == self._dist.project_name
+            assert (self._name is None or
+                    self._name == canonicalize_name(self._dist.project_name))
             assert (self._version is None or
                     self._version == self.dist.parsed_version)
         return self._dist
diff --git a/src/pip/_internal/resolution/resolvelib/provider.py b/src/pip/_internal/resolution/resolvelib/provider.py
index 21c3ecbb6..981646ea9 100644
--- a/src/pip/_internal/resolution/resolvelib/provider.py
+++ b/src/pip/_internal/resolution/resolvelib/provider.py
@@ -38,6 +38,14 @@ class PipProvider(AbstractProvider):
 
     def get_install_requirement(self, c):
         # type: (Candidate) -> InstallRequirement
+
+        # The base Candidate class does not have an _ireq attribute, so we
+        # fetch it dynamically here, to satisfy mypy. In practice, though, we
+        # only ever deal with LinkedCandidate objects at the moment, which do
+        # have an _ireq attribute.  When we have a candidate type for installed
+        # requirements we should probably review this.
+        #
+        # TODO: Longer term, make a proper interface for this on the candidate.
         return getattr(c, "_ireq", None)
 
     def identify(self, dependency):
diff --git a/src/pip/_internal/resolution/resolvelib/requirements.py b/src/pip/_internal/resolution/resolvelib/requirements.py
index d5965e3e1..4adc8a09a 100644
--- a/src/pip/_internal/resolution/resolvelib/requirements.py
+++ b/src/pip/_internal/resolution/resolvelib/requirements.py
@@ -48,6 +48,7 @@ class ExplicitRequirement(Requirement):
     @property
     def name(self):
         # type: () -> str
+        # No need to canonicalise - the candidate did this
         return self.candidate.name
 
     def find_matches(self):