From d62bef43623eeada2eef810c824d95b4797e3c70 Mon Sep 17 00:00:00 2001
From: Mike <mikeh@blur.com>
Date: Fri, 17 May 2019 11:06:59 -0700
Subject: [PATCH] Document caveats for UNC paths in uninstall and add .pth unit
 tests

---
 news/6516.doc                          |  1 +
 src/pip/_internal/req/req_uninstall.py |  5 ++++
 tests/unit/test_req_uninstall.py       | 35 +++++++++++++++++++++++++-
 3 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 news/6516.doc

diff --git a/news/6516.doc b/news/6516.doc
new file mode 100644
index 00000000000..e8b880ef4b4
--- /dev/null
+++ b/news/6516.doc
@@ -0,0 +1 @@
+Document caveats for UNC paths in uninstall and add .pth unit tests.
diff --git a/src/pip/_internal/req/req_uninstall.py b/src/pip/_internal/req/req_uninstall.py
index 733301cee6c..359fb7cded7 100644
--- a/src/pip/_internal/req/req_uninstall.py
+++ b/src/pip/_internal/req/req_uninstall.py
@@ -593,6 +593,11 @@ def add(self, entry):
         # backslashes.  This is correct for entries that describe absolute
         # paths outside of site-packages, but all the others use forward
         # slashes.
+        # os.path.splitdrive is used instead of os.path.isabs because isabs
+        # treats non-absolute paths with drive letter markings like c:foo\bar
+        # as absolute paths. It also does not recognize UNC paths if they don't
+        # have more than "\\sever\share". Valid examples: "\\server\share\" or
+        # "\\server\share\folder". Python 2.7.8+ support UNC in splitdrive.
         if WINDOWS and not os.path.splitdrive(entry)[0]:
             entry = entry.replace('\\', '/')
         self.entries.add(entry)
diff --git a/tests/unit/test_req_uninstall.py b/tests/unit/test_req_uninstall.py
index 37edb7dfa42..99b315b1550 100644
--- a/tests/unit/test_req_uninstall.py
+++ b/tests/unit/test_req_uninstall.py
@@ -1,11 +1,12 @@
 import os
+import sys
 
 import pytest
 from mock import Mock
 
 import pip._internal.req.req_uninstall
 from pip._internal.req.req_uninstall import (
-    StashedUninstallPathSet, UninstallPathSet, compact,
+    StashedUninstallPathSet, UninstallPathSet, UninstallPthEntries, compact,
     compress_for_output_listing, compress_for_rename, uninstallation_paths,
 )
 from tests.lib import create_file
@@ -129,6 +130,38 @@ def test_add(self, tmpdir, monkeypatch):
         ups.add(file_nonexistent)
         assert ups.paths == {file_extant}
 
+    def test_add_pth(self, tmpdir, monkeypatch):
+        monkeypatch.setattr(pip._internal.req.req_uninstall, 'is_local',
+                            mock_is_local)
+        # Fix case for windows tests
+        tmpdir = os.path.normcase(tmpdir)
+        on_windows = sys.platform == 'win32'
+        pth_file = os.path.join(tmpdir, 'foo.pth')
+        relative = '../../example'
+        if on_windows:
+            share = '\\\\example\\share\\'
+            share_com = '\\\\example.com\\share\\'
+        # Create a .pth file for testing
+        with open(pth_file, 'w') as f:
+            f.writelines([tmpdir, '\n',
+                          relative, '\n'])
+            if on_windows:
+                f.writelines([share, '\n',
+                              share_com, '\n'])
+        # Add paths to be removed
+        pth = UninstallPthEntries(pth_file)
+        pth.add(tmpdir)
+        pth.add(relative)
+        if on_windows:
+            pth.add(share)
+            pth.add(share_com)
+        # Check that the paths were added to entries
+        if on_windows:
+            check = set([tmpdir, relative, share, share_com])
+        else:
+            check = set([tmpdir, relative])
+        assert pth.entries == check
+
     @pytest.mark.skipif("sys.platform == 'win32'")
     def test_add_symlink(self, tmpdir, monkeypatch):
         monkeypatch.setattr(pip._internal.req.req_uninstall, 'is_local',