Adds test for AdjacentTempDirectory._generate_names

src/pip/_internal/req/req_uninstall.py

@@ -17,7 +17,7 @@ from pip._internal.utils.misc import (
     FakeFile, ask, dist_in_usersite, dist_is_local, egg_link_path, is_local,
     normalize_path, renames,
 )
-from pip._internal.utils.temp_dir import TempDirectory, AdjacentTempDirectory
+from pip._internal.utils.temp_dir import AdjacentTempDirectory
 
 logger = logging.getLogger(__name__)
 
@@ -105,7 +105,7 @@ def compress_for_rename(paths):
     remaining = set(paths)
     unchecked = sorted(set(os.path.split(p)[0] for p in remaining), key=len)
     wildcards = set()
-    
+
     def norm_join(*a):
         return os.path.normcase(os.path.join(*a))
 

src/pip/_internal/utils/temp_dir.py

@@ -3,7 +3,6 @@ from __future__ import absolute_import
 import itertools
 import logging
 import os.path
-import shutil
 import tempfile
 
 from pip._internal.utils.misc import rmtree
@@ -115,8 +114,12 @@ class AdjacentTempDirectory(TempDirectory):
         package).
         """
         for i in range(1, len(name)):
-            for candidate in itertools.permutations(cls.LEADING_CHARS, i):
-                yield ''.join(candidate) + name[i:]
+            if name[i] in cls.LEADING_CHARS:
+                continue
+            for candidate in itertools.combinations_with_replacement(cls.LEADING_CHARS, i):
+                new_name = ''.join(candidate) + name[i:]
+                if new_name != name:
+                    yield new_name
 
     def create(self):
         root, name = os.path.split(self.original)
@@ -136,4 +139,3 @@ class AdjacentTempDirectory(TempDirectory):
                 tempfile.mkdtemp(prefix="pip-{}-".format(self.kind))
             )
         logger.debug("Created temporary directory: {}".format(self.path))
-

tests/unit/test_utils.py

@@ -4,6 +4,7 @@
 util tests
 
 """
+import itertools
 import os
 import shutil
 import stat
@@ -29,7 +30,7 @@ from pip._internal.utils.misc import (
     split_auth_from_netloc, untar_file, unzip_file,
 )
 from pip._internal.utils.packaging import check_dist_requires_python
-from pip._internal.utils.temp_dir import TempDirectory
+from pip._internal.utils.temp_dir import TempDirectory, AdjacentTempDirectory
 
 
 class Tests_EgglinkPath:
@@ -547,6 +548,32 @@ class TestTempDirectory(object):
         assert tmp_dir.path is None
         assert not os.path.exists(created_path)
 
+    @pytest.mark.parametrize("name",
+        [
+            "ABC",
+            "ABC.dist-info",
+            "_+-",
+            "_package",
+        ])
+    def test_adjacent_directory_names(self, name):
+        names = lambda: AdjacentTempDirectory._generate_names(name)
+        chars = AdjacentTempDirectory.LEADING_CHARS
+
+        # Ensure many names are unique
+        # (For long *name*, this sequence can be extremely long.
+        # However, since we're only ever going to take the first
+        # result that works, provided there are many of those
+        # and that shorter names result in totally unique sets,
+        # it's okay to skip part of the test.)
+        some_names = list(itertools.islice(names(), 10000))
+        assert len(some_names) == len(set(some_names))
+
+        # Ensure original name does not appear
+        assert not any(n == name for n in names())
+
+        # Check the first group are correct
+        assert all(x == y for x, y in zip(some_names, [c + name[1:] for c in chars]))
+
 
 class TestGlibc(object):
     def test_manylinux1_check_glibc_version(self):