make easy_install.uncache_zipdir() remove more stale zipimporter instances

Since paths are case-insensitive on Windows, zipped egg modules may be loaded
using different but equivalent paths. Importing each such different path causes
a new zipimporter to be instantiated. Removing cached zipimporter instances must
then not forget about removing those created for differently spelled paths to
the same replaced egg.

Other missed zipimporter instances are those used to access zipped eggs stored
inside zipped eggs. When clearing zipimporter instances got a given path, we
need to clear all the instances related to any of its subpaths as well.

--HG--
extra : rebase_source : 86aeadd1e639fbc83d27a0c551fdc2b8a68a6f85

1 files changed, 14 insertions, 12 deletions

diff --git a/setuptools/command/easy_install.py b/setuptools/command/easy_install.py
index 8c281590..d4bb2b90 100755
--- a/setuptools/command/easy_install.py
+++ b/setuptools/command/easy_install.py
@@ -1597,18 +1597,20 @@ def uncache_zipdir(path):
     whomever is in charge of maintaining that cache.
 
     """
-    _uncache(path, zipimport._zip_directory_cache)
-    _uncache(path, sys.path_importer_cache)
-
-def _uncache(path, cache):
-    if path in cache:
-        del cache[path]
-    else:
-        normalized_path = normalize_path(path)
-        for p in cache:
-            if normalize_path(p) == normalized_path:
-                del cache[p]
-                return
+    normalized_path = normalize_path(path)
+    _uncache(normalized_path, zipimport._zip_directory_cache)
+    _uncache(normalized_path, sys.path_importer_cache)
+
+def _uncache(normalized_path, cache):
+    to_remove = []
+    prefix_len = len(normalized_path)
+    for p in cache:
+        np = normalize_path(p)
+        if (np.startswith(normalized_path) and
+                np[prefix_len:prefix_len + 1] in (os.sep, '')):
+            to_remove.append(p)
+    for p in to_remove:
+        del cache[p]
 
 def is_python(text, filename='<string>'):
     "Is this string a valid Python script?"