Fix #837

Normalize case for prefix paths before checking them

2 files changed, 4 insertions, 1 deletions

diff --git a/docs/changes.rst b/docs/changes.rst
index 9c2c2b9..1f5c73b 100644
--- a/docs/changes.rst
+++ b/docs/changes.rst
@@ -6,6 +6,8 @@ Release History
 
 * Supress any errors from `unset` on different shells (:pull:`843`)
 
+* Normalize letter case for prefix path checking. Fixes :issue:`837`
+
 14.0.1 (2016-01-21)
 -------------------
 
diff --git a/virtualenv.py b/virtualenv.py
index 513f12d..c8148f5 100755
--- a/virtualenv.py
+++ b/virtualenv.py
@@ -975,9 +975,10 @@ def change_prefix(filename, dst_prefix):
         prefixes.append(sys.base_prefix)
     prefixes = list(map(os.path.expanduser, prefixes))
     prefixes = list(map(os.path.abspath, prefixes))
+    prefixes = list(map(os.path.normcase, prefixes))
     # Check longer prefixes first so we don't split in the middle of a filename
     prefixes = sorted(prefixes, key=len, reverse=True)
-    filename = os.path.abspath(filename)
+    filename = os.path.normcase(os.path.abspath(filename))
     for src_prefix in prefixes:
         if filename.startswith(src_prefix):
             _, relpath = filename.split(src_prefix, 1)