Revert "Fixed #23384 -- Allowed overriding part of a dictionary-type setting"

This reverts commit 66757fee7e921ad4c35e0b3f80c25e026100b31c.
Discussions have led to think that this functionality does not
bring significant benefits to justify the added complexity.
Read also discussions on ticket #22734.

1 files changed, 0 insertions, 20 deletions

diff --git a/django/utils/datastructures.py b/django/utils/datastructures.py
index ad8792d192..2efcd00eb0 100644
--- a/django/utils/datastructures.py
+++ b/django/utils/datastructures.py
@@ -244,26 +244,6 @@ class SortedDict(dict):
         self.keyOrder = []
 
 
-def dict_merge(a, b):
-    """
-    Utility to recursively merge two dicts, taking care not to overwrite subkeys
-    (which would happen with dict.update), but keeping existing key including
-    those from subdictionaries (optionally opted-out if a `_clear_defaults` key
-    is present).
-    Thanks Ross McFarland (https://www.xormedia.com/recursively-merge-dictionaries-in-python/)
-    """
-    if b.get('_clear_defaults'):
-        return copy.deepcopy(b)
-
-    result = copy.deepcopy(a)
-    for key, value in six.iteritems(b):
-        if key in a and isinstance(result[key], dict):
-            result[key] = dict_merge(result[key], value)
-        else:
-            result[key] = value
-    return result
-
-
 class OrderedSet(object):
     """
     A set which keeps the ordering of the inserted items.