Fix #3008: `linkcheck` builder ignores self-signed certificate URL

CHANGES

@@ -10,6 +10,8 @@ Incompatible changes
 Features added
 --------------
 
+* #3008: ``linkcheck`` builder ignores self-signed certificate URL
+
 Bugs fixed
 ----------
 

sphinx/builders/linkcheck.py

@@ -35,7 +35,7 @@ from sphinx.builders import Builder
 from sphinx.util import encode_uri
 from sphinx.util.console import purple, red, darkgreen, darkgray, \
     darkred, turquoise
-from sphinx.util.requests import requests, useragent_header
+from sphinx.util.requests import requests, useragent_header, is_ssl_error
 
 
 class AnchorCheckParser(HTMLParser):
@@ -152,6 +152,9 @@ class CheckExternalLinksBuilder(Builder):
                 else:
                     return 'broken', str(err), 0
             except Exception as err:
+                if is_ssl_error(err):
+                    return 'ignored', str(err), 0
+                else:
                     return 'broken', str(err), 0
             if response.url.rstrip('/') == req_url.rstrip('/'):
                 return 'working', '', 0
@@ -211,6 +214,9 @@ class CheckExternalLinksBuilder(Builder):
         if lineno:
             self.info('(line %4d) ' % lineno, nonl=1)
         if status == 'ignored':
+            if info:
+                self.info(darkgray('-ignored- ') + uri + ': ' + info)
+            else:
                 self.info(darkgray('-ignored- ') + uri)
         elif status == 'local':
             self.info(darkgray('-local-   ') + uri)

sphinx/util/requests.py

@@ -14,6 +14,7 @@ from __future__ import absolute_import
 import requests
 import warnings
 import pkg_resources
+from requests.packages.urllib3.exceptions import SSLError
 
 # try to load requests[security]
 try:
@@ -41,3 +42,14 @@ except pkg_resources.UnknownExtra:
 
 useragent_header = [('User-Agent',
                      'Mozilla/5.0 (X11; Linux x86_64; rv:25.0) Gecko/20100101 Firefox/25.0')]
+
+
+def is_ssl_error(exc):
+    if isinstance(exc, SSLError):
+        return True
+    else:
+        args = getattr(exc, 'args', [])
+        if args and isinstance(args[0], SSLError):
+            return True
+        else:
+            return False