Fix - normalize cwd path on dist path check (#4088)

newsfragments/4088.bugfix.rst

@@ -0,0 +1,4 @@
+Fixed path comparison in ``easy_install`` via normalization.
+(This affects only deprecated calls to ``python setup.py install/develop``,
+users are still encouraged to use ``python -m build`` or ``pip install -e .``
+with build isolation).

setuptools/command/easy_install.py

@@ -1247,26 +1247,29 @@ def update_pth(self, dist):  # noqa: C901  # is too complex (11)  # FIXME
         if self.pth_file is None:
             return
 
+        dist_location = normalize_path(dist.location)
+
         for d in self.pth_file[dist.key]:  # drop old entries
-            if not self.multi_version and d.location == dist.location:
+            d_location = normalize_path(d.location)
+            if not self.multi_version and d_location == dist_location:
                 continue
 
             log.info("Removing %s from easy-install.pth file", d)
             self.pth_file.remove(d)
-            if d.location in self.shadow_path:
-                self.shadow_path.remove(d.location)
+            if d_location in map(normalize_path, self.shadow_path):
+                self.shadow_path.remove(d_location)
 
         if not self.multi_version:
-            if dist.location in self.pth_file.paths:
+            if dist_location in self.pth_file.paths:
                 log.info(
                     "%s is already the active version in easy-install.pth",
                     dist,
                 )
             else:
                 log.info("Adding %s to easy-install.pth file", dist)
                 self.pth_file.add(dist)  # add new entry
-                if dist.location not in self.shadow_path:
-                    self.shadow_path.append(dist.location)
+                if dist_location not in map(normalize_path, self.shadow_path):
+                    self.shadow_path.append(dist_location)
 
         if self.dry_run:
             return
@@ -1282,7 +1285,7 @@ def update_pth(self, dist):  # noqa: C901  # is too complex (11)  # FIXME
         if os.path.islink(filename):
             os.unlink(filename)
         with open(filename, 'wt') as f:
-            f.write(self.pth_file.make_relative(dist.location) + '\n')
+            f.write(self.pth_file.make_relative(dist_location) + '\n')
 
     def unpack_progress(self, src, dst):
         # Progress filter for unpacking
@@ -1713,21 +1716,23 @@ def _wrap_lines(lines):
 
     def add(self, dist):
         """Add `dist` to the distribution map"""
-        new_path = dist.location not in self.paths and (
-            dist.location not in self.sitedirs
+        dist_location = normalize_path(dist.location)
+        new_path = dist_location not in map(normalize_path, self.paths) and (
+            dist_location not in map(normalize_path, self.sitedirs)
             or
             # account for '.' being in PYTHONPATH
-            dist.location == os.getcwd()
+            dist_location == normalize_path(os.getcwd())
         )
         if new_path:
-            self.paths.append(dist.location)
+            self.paths.append(dist_location)
             self.dirty = True
         super().add(dist)
 
     def remove(self, dist):
         """Remove `dist` from the distribution map"""
-        while dist.location in self.paths:
-            self.paths.remove(dist.location)
+        dist_location = normalize_path(dist.location)
+        while dist_location in map(normalize_path, self.paths):
+            self.paths.remove(dist_location)
             self.dirty = True
         super().remove(dist)
 

setuptools/tests/test_easy_install.py

@@ -316,6 +316,30 @@ def test_add_from_site_is_ignored(self):
         pth.add(PRDistribution(location))
         assert not pth.dirty
 
+    def test_add_remove_for_normalized_path(self):
+        """
+        In windows, path is not case sensitive,
+        This is test when the distribution path is cwd and normalized.
+        """
+        if sys.platform.startswith('win'):  # pragma: no cover
+            path_org = 'C:/Location/package'
+        else:
+            path_org = '/Location/package'
+        path_norm = pkg_resources.normalize_path(path_org)
+
+        pth = PthDistributions('test-package', [path_org])
+        dist = PRDistribution(location=path_norm, version='1.0')
+
+        with mock.patch('os.getcwd') as mock_getcwd:
+            mock_getcwd.return_value = path_org
+            assert not pth.dirty
+            pth.add(dist)
+            assert pth.dirty
+
+        assert len(pth.paths) == 1
+        pth.remove(dist)
+        assert len(pth.paths) == 0
+
     def test_many_pth_distributions_merge_together(self, tmpdir):
         """
         If the pth file is modified under the hood, then PthDistribution