Fix malformed value parsing for Content-Type (#7309)

Author: nateprewitt

src/requests/utils.py

@@ -502,26 +502,23 @@ def get_encodings_from_content(content):
 
 
 def _parse_content_type_header(header):
-    """Returns content type and parameters from given header
+    """Returns content type and parameters from given header.
 
     :param header: string
     :return: tuple containing content type and dictionary of
-         parameters
+         parameters.
     """
 
     tokens = header.split(";")
     content_type, params = tokens[0].strip(), tokens[1:]
     params_dict = {}
-    items_to_strip = "\"' "
+    strip_chars = "\"' "
 
     for param in params:
         param = param.strip()
-        if param:
-            key, value = param, True
-            index_of_equals = param.find("=")
-            if index_of_equals != -1:
-                key = param[:index_of_equals].strip(items_to_strip)
-                value = param[index_of_equals + 1 :].strip(items_to_strip)
+        if param and (idx := param.find("=")) != -1:
+            key = param[:idx].strip(strip_chars)
+            value = param[idx + 1 :].strip(strip_chars)
             params_dict[key.lower()] = value
     return content_type, params_dict
 

tests/test_utils.py

@@ -596,7 +596,6 @@ def test_parse_dict_header(value, expected):
                 {
                     "boundary": "something",
                     "boundary2": "something_else",
-                    "no_equals": True,
                 },
             ),
         ),
@@ -607,7 +606,6 @@ def test_parse_dict_header(value, expected):
                 {
                     "boundary": "something",
                     "boundary2": "something_else",
-                    "no_equals": True,
                 },
             ),
         ),
@@ -618,7 +616,6 @@ def test_parse_dict_header(value, expected):
                 {
                     "boundary": "something",
                     "boundary2": "something_else",
-                    "no_equals": True,
                 },
             ),
         ),
@@ -629,7 +626,6 @@ def test_parse_dict_header(value, expected):
                 {
                     "boundary": "something",
                     "boundary2": "something_else",
-                    "no_equals": True,
                 },
             ),
         ),
@@ -649,6 +645,10 @@ def test__parse_content_type_header(value, expected):
             "utf-8",
         ),
         (CaseInsensitiveDict({"content-type": "text/plain"}), "ISO-8859-1"),
+        (
+            CaseInsensitiveDict({"content-type": "text/html; charset"}),
+            "ISO-8859-1",
+        ),
     ),
 )
 def test_get_encoding_from_headers(value, expected):