Catch and ignore TLS verification exception for IP-address hosts

Fixes GH-2092

scrapy/core/downloader/tls.py

@@ -48,6 +48,11 @@ try:
                         'Remote certificate is not valid for hostname "{}"; {}'.format(
                             self._hostnameASCII, e))
 
+                except ValueError as e:
+                    logger.warning(
+                        'SSL/TLS verification failed for hostname "{}"; {}'.format(
+                            self._hostnameASCII, e))
+
 except ImportError:
     # ImportError should not matter for older Twisted versions
     # as the above is not used in the fallback ScrapyClientContextFactory

tests/test_downloader_handlers.py

@@ -335,6 +335,14 @@ class Https11WrongHostnameTestCase(Http11TestCase):
     certfile = 'keys/example-com.cert.pem'
 
 
+class Https11InvalidDNSId(Https11TestCase):
+    """Connect to HTTPS hosts with IP while certificate uses domain names IDs."""
+
+    def setUp(self):
+        super(Https11InvalidDNSId, self).setUp()
+        self.host = '127.0.0.1'
+
+
 class Http11MockServerTestCase(unittest.TestCase):
     """HTTP 1.1 test case with MockServer"""
     if twisted_version < (11, 1, 0):