Comma separate repeated request headers.

RFC 2616 says that only headers that are allowed to have comma separated
values are acceptable for repetition. Though it doesn't specify an error
condition for that situation. I reckon the cleanest way would be to list
the headers that are acceptable for repetition, and return a 400 Bad
Request.

gunicorn/http/parser.py

@@ -96,7 +96,11 @@ class Parser(object):
         """ parse header line"""
         name, value = line.split(":", 1)
         name = normalize_name(name.strip())
-        hdrs[name] = value.rsplit("\r\n",1)[0].strip()
+        value = value.rsplit("\r\n",1)[0].strip()
+        if name in hdrs:
+            hdrs[name] = "%s, %s" % (hdrs[name], value)
+        else:
+            hdrs[name] = value
         return name
       
     @property

tests/001-test-parser.py

@@ -192,3 +192,17 @@ def test_011(buf, p):
         if chunk:
             body += chunk
     t.eq(body, "hello world")
+
+@t.request("017.http")
+def test_017(buf, p):
+    headers = []
+    i = p.filter_headers(headers, buf)
+    t.ne(i, -1)
+    t.eq(p.method, "GET")
+    t.eq(p.version, (1, 0))
+    t.eq(p.path, "/stuff/here")
+    t.eq(p.query_string, "foo=bar")
+    t.eq(p.is_chunked, False)
+    t.eq(p._chunk_eof, False)
+    t.eq(p.body_eof(), True)
+    t.eq(p.headers, [("If-Match", "bazinga!, large-sound")])

tests/requests/017.http

@@ -0,0 +1,4 @@
+GET /stuff/here?foo=bar HTTP/1.0\r\n
+If-Match: bazinga!\r\n
+If-Match: large-sound\r\n
+\r\n