From 3c004075b1d4fe4aa1ffc3f7d699dd9525bc6c02 Mon Sep 17 00:00:00 2001
From: Illia Volochii <illia.volochii@gmail.com>
Date: Thu, 28 Jan 2021 07:28:14 +0200
Subject: [PATCH] Fixed #32389 -- Fixed ResponseHeaders crash when data is not
 mapping.

---
 django/http/response.py     | 9 ++++-----
 tests/httpwrappers/tests.py | 4 ++++
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/django/http/response.py b/django/http/response.py
index 0d23c1312f..1c22edaff3 100644
--- a/django/http/response.py
+++ b/django/http/response.py
@@ -16,7 +16,9 @@ from django.core.exceptions import DisallowedRedirect
 from django.core.serializers.json import DjangoJSONEncoder
 from django.http.cookie import SimpleCookie
 from django.utils import timezone
-from django.utils.datastructures import CaseInsensitiveMapping
+from django.utils.datastructures import (
+    CaseInsensitiveMapping, _destruct_iterable_mapping_values,
+)
 from django.utils.encoding import iri_to_uri
 from django.utils.http import http_date
 from django.utils.regex_helper import _lazy_re_compile
@@ -31,10 +33,7 @@ class ResponseHeaders(CaseInsensitiveMapping):
         correctly encoded.
         """
         if not isinstance(data, Mapping):
-            data = {
-                k: v
-                for k, v in CaseInsensitiveMapping._destruct_iterable_mapping_values(data)
-            }
+            data = {k: v for k, v in _destruct_iterable_mapping_values(data)}
         self._store = {}
         for header, value in data.items():
             self[header] = value
diff --git a/tests/httpwrappers/tests.py b/tests/httpwrappers/tests.py
index cbf8b7d586..728e879b5c 100644
--- a/tests/httpwrappers/tests.py
+++ b/tests/httpwrappers/tests.py
@@ -835,6 +835,10 @@ class HttpResponseHeadersTestCase(SimpleTestCase):
         # del doesn't raise a KeyError on nonexistent headers.
         del response['X-Foo']
 
+    def test_headers_as_iterable_of_tuple_pairs(self):
+        response = HttpResponse(headers=(('X-Foo', 'bar'),))
+        self.assertEqual(response['X-Foo'], 'bar')
+
     def test_headers_bytestring(self):
         response = HttpResponse()
         response['X-Foo'] = b'bar'