fix[web]: fix optional whitespace parsing of Accept-Language header

HTTP allows OWS between parameters:
`Accept-Language: de-DE; q=0.1, en-US; q=0.2`

diff --git a/tornado/web.py b/tornado/web.py
index ddf1de746e0329ec6ff0f4951d51fa4e8ac41853..b3efce998e7630a147119190ad364ffe80b8803c 100644 (file)
--- a/tornado/web.py
+++ b/tornado/web.py
@@ -1286,9 +1286,9 @@ class RequestHandler(object):
             locales = []
             for language in languages:
                 parts = language.strip().split(";")
-                if len(parts) > 1 and parts[1].startswith("q="):
+                if len(parts) > 1 and parts[1].strip().startswith("q="):
                     try:
-                        score = float(parts[1][2:])
+                        score = float(parts[1].strip()[2:])
                     except (ValueError, TypeError):
                         score = 0.0
                 else: