From 92fe51c0afd9239388d2c8bb17dc46babdf7881f Mon Sep 17 00:00:00 2001
From: Nate Prewitt <nateprewitt@users.noreply.github.com>
Date: Tue, 28 Jun 2016 13:22:00 -0600
Subject: [PATCH] adding asserted_encoding check on None type encoding to match
 text() behavior (#3362)

---
 requests/utils.py      | 17 ++++++++++++-----
 tests/test_requests.py |  7 +++++++
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/requests/utils.py b/requests/utils.py
index 8d17b6b2..62d023fa 100644
--- a/requests/utils.py
+++ b/requests/utils.py
@@ -358,13 +358,20 @@ def get_encoding_from_headers(headers):
 
 def stream_decode_response_unicode(iterator, r):
     """Stream decodes a iterator."""
+    encoding = r.encoding
 
-    if r.encoding is None:
-        for item in iterator:
-            yield item
-        return
+    if encoding is None:
+        encoding = r.apparent_encoding
+
+    try:
+        decoder = codecs.getincrementaldecoder(encoding)(errors='replace')
+    except (LookupError, TypeError):
+        # A LookupError is raised if the encoding was not found which could
+        # indicate a misspelling or similar mistake.
+        #
+        # A TypeError can be raised if encoding is None
+        raise UnicodeError("Unable to decode contents with encoding %s." % encoding)
 
-    decoder = codecs.getincrementaldecoder(r.encoding)(errors='replace')
     for chunk in iterator:
         rv = decoder.decode(chunk)
         if rv:
diff --git a/tests/test_requests.py b/tests/test_requests.py
index d2a2714a..4393814f 100755
--- a/tests/test_requests.py
+++ b/tests/test_requests.py
@@ -980,6 +980,13 @@ class TestRequests:
         chunks = r.iter_content(decode_unicode=True)
         assert all(isinstance(chunk, str) for chunk in chunks)
 
+        # check for encoding value of None
+        r = requests.Response()
+        r.raw = io.BytesIO(b'the content')
+        r.encoding = None
+        chunks = r.iter_content(decode_unicode=True)
+        assert all(isinstance(chunk, str) for chunk in chunks)
+
     def test_response_chunk_size_int(self):
         """Ensure that chunk_size is passed as an integer, otherwise
         raise a TypeError.