Fixed #6465 -- Tweaked MergeDict.getlist() to work with Django's MultiValueDict…

Fixed #6465 -- Tweaked MergeDict.getlist() to work with Django's MultiValueDict class. Thanks, Matt McClanahan.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@7062 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/utils/datastructures.py

@@ -2,6 +2,9 @@ class MergeDict(object):
     """
     A simple class for creating new "virtual" dictionaries that actually look
     up values in more than one dictionary, passed in the constructor.
+
+    If a key appears in more than one of the passed in dictionaries, only the
+    first occurrence will be used.
     """
     def __init__(self, *dicts):
         self.dicts = dicts
@@ -25,11 +28,9 @@ class MergeDict(object):
 
     def getlist(self, key):
         for dict_ in self.dicts:
-            try:
+            if key in dict_.keys():
                 return dict_.getlist(key)
-            except KeyError:
-                pass
-        raise KeyError
+        return []
 
     def items(self):
         item_list = []

tests/regressiontests/datastructures/tests.py

@@ -20,6 +20,19 @@
 >>> md2['chris']
 'cool'
 
+MergeDict can merge MultiValueDicts
+>>> multi1 = MultiValueDict({'key1': ['value1'], 'key2': ['value2', 'value3']})
+>>> multi2 = MultiValueDict({'key2': ['value4'], 'key4': ['value5', 'value6']})
+>>> mm = MergeDict(multi1, multi2)
+
+# Although 'key2' appears in both dictionaries, only the first value is used.
+>>> mm.getlist('key2')
+['value2', 'value3']
+>>> mm.getlist('key4')
+['value5', 'value6']
+>>> mm.getlist('undefined')
+[]
+
 ### MultiValueDict ##########################################################
 
 >>> d = MultiValueDict({'name': ['Adrian', 'Simon'], 'position': ['Developer']})