From d2e9ea0c88b7578c5fc8d4d37e5df9d078e9b884 Mon Sep 17 00:00:00 2001
From: Paul Tremberth <paul.tremberth@gmail.com>
Date: Fri, 13 Jan 2017 16:17:51 +0100
Subject: [PATCH] Enforce DNS resolution timeout

---
 scrapy/resolver.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/scrapy/resolver.py b/scrapy/resolver.py
index 3954fd977..4f4f0b04f 100644
--- a/scrapy/resolver.py
+++ b/scrapy/resolver.py
@@ -16,8 +16,11 @@ class CachingThreadedResolver(ThreadedResolver):
     def getHostByName(self, name, timeout=None):
         if name in dnscache:
             return defer.succeed(dnscache[name])
-        if not timeout:
-            timeout = self.timeout
+        # in Twisted<=16.6, getHostByName() is always called with
+        # a default timeout of 60s (actually passed as (1, 3, 11, 45) tuple),
+        # so the input argument above is simply overridden
+        # to enforce Scrapy's DNS_TIMEOUT setting's value
+        timeout = (self.timeout,)
         d = super(CachingThreadedResolver, self).getHostByName(name, timeout)
         d.addCallback(self._cache_result, name)
         return d