Fix additionalProperties with patternProperties present.

Closes #24.

Author: Julian

jsonschema.py

@@ -391,8 +391,7 @@ def validate_additionalProperties(self, aP, instance, schema):
         if not self.is_type(instance, "object"):
             return
 
-        # no viewkeys in <2.7, and pypy seems to fail on vk - vk anyhow, so...
-        extras = set(instance) - set(schema.get("properties", {}))
+        extras = set(_find_additional_properties(instance, schema))
 
         if self.is_type(aP, "object"):
             for extra in extras:
@@ -596,6 +595,26 @@ def __repr__(self):
         return "<%s (%s errors)>" % (self.__class__.__name__, len(self))
 
 
+def _find_additional_properties(instance, schema):
+    """
+    Return the set of additional properties for the given ``instance``.
+
+    Weeds out properties that should have been validated by ``properties`` and
+    / or ``patternProperties``.
+
+    Assumes ``instance`` is dict-like already.
+
+    """
+
+    properties = schema.get("properties", {})
+    patterns = "|".join(schema.get("patternProperties", {}))
+    for property in instance:
+        if property not in properties:
+            if patterns and re.search(patterns, property):
+                continue
+            yield property
+
+
 def _extras_msg(extras):
     """
     Create an error message for extra items or properties.

tests.py

@@ -282,6 +282,26 @@ def additionalProperties(self, aP):
         with self.assertRaises(ValidationError):
             validate({"foo" : 1, "bar" : "baz", "quux" : "boom"}, schema)
 
+    # A horrible name and horrible test. I will repent.
+    # See https://groups.google.com/d/msg/json-schema/Q5F30CZtMb4/yk_niLnsdQ0J
+    p_pP_aP = parametrized(
+        ("property_validates_property", "valid", {"foo" : [1, 2]}),
+        ("property_invalidates_property", "invalid", {"foo" : [1, 2, 3, 4]}),
+        ("patternProperty_invalidates_property", "invalid", {"foo" : []}),
+        ("patternProperty_validates_nonproperty", "valid", {"fxo" : [1, 2]}),
+        ("patternProperty_invalidates_nonproperty", "invalid", {"fxo" : []}),
+        ("additionalProperty_ignores_property", "valid", {"bar" : []}),
+        ("additionalProperty_validates_others", "valid", {"quux" : 3}),
+        ("additionalProperty_invalidates_others", "invalid", {"quux" : "foo"}),
+    )(validation_test(
+        properties={
+            "foo" : {"type" : "array", "maxItems" : 3},
+            "bar" : {"type" : "array"}
+        },
+        patternProperties={"f.o" : {"minItems" : 2}},
+        additionalProperties={"type" : "integer"},
+    ))
+
     items = parametrized(
         ("", "valid", [1, 2, 3]),
         ("wrong_type", "invalid", [1, "x"]),