fix caching of file-categorization logic

CONTRIBUTING.rst

@@ -163,6 +163,7 @@ their individual contributions.
 * `Alex Stapleton <https://www.github.com/public>`_
 * `Alex Willmer <https://github.com/moreati>`_ (alex@moreati.org.uk)
 * `Ben Peterson <https://github.com/killthrush>`_ (killthrush@hotmail.com_)
+* `Buck Evan, copyright Google LLC <https://github.com/bukzor>`_
 * `Charles O'Farrell <https://www.github.com/charleso>`_
 * `Charlie Tanksley <https://www.github.com/charlietanksley>`_
 * `Chris Down  <https://chrisdown.name>`_

RELEASE.rst

@@ -0,0 +1,4 @@
+RELEASE_TYPE: patch
+
+This release fixes :issue:`1044`, which slowed tests by up to 6%
+due to broken caching.

src/hypothesis/internal/escalation.py

@@ -34,13 +34,15 @@ def belongs_to(package):
     cache = {text_type: {}, binary_type: {}}
 
     def accept(filepath):
+        ftype = type(filepath)
         try:
-            return cache[type(filepath)][filepath]
+            return cache[ftype][filepath]
         except KeyError:
             pass
-        filepath = encoded_filepath(filepath)
-        result = os.path.abspath(filepath).startswith(root)
-        cache[type(filepath)][filepath] = result
+        new_filepath = encoded_filepath(filepath)
+        result = os.path.abspath(new_filepath).startswith(root)
+        cache[ftype][filepath] = result
+        cache[type(new_filepath)][new_filepath] = result
         return result
     accept.__name__ = 'is_%s_file' % (package.__name__,)
     return accept