bugdown: Add option to support "file:///" as hyperlink.

This contains contributions from Tim Abbott and Igor Tokarev.

Fixes #380.

zerver/lib/bugdown/__init__.py

@@ -719,7 +719,7 @@ def sanitize_url(url):
     if not scheme:
         return sanitize_url('http://' + url)
 
-    locless_schemes = ['mailto', 'news']
+    locless_schemes = ['mailto', 'news', 'file']
     if netloc == '' and scheme not in locless_schemes:
         # This fails regardless of anything else.
         # Return immediately to save additional proccessing
@@ -729,7 +729,7 @@ def sanitize_url(url):
     # appears to have a netloc.  Additionally there are plenty of other
     # schemes that do weird things like launch external programs.  To be
     # on the safe side, we whitelist the scheme.
-    if scheme not in ('http', 'https', 'ftp', 'mailto'):
+    if scheme not in ('http', 'https', 'ftp', 'mailto', 'file'):
         return None
 
     # Upstream code scans path, parameters, and query for colon characters
@@ -1079,12 +1079,14 @@ class Bugdown(markdown.Extension):
                     %s           # zero-to-6 sets of paired parens
                 )?)              # Path is optional
                 | (?:[\w.-]+\@[\w.-]+\.[\w]+) # Email is separate, since it can't have a path
+                %s               # File path start with file:///, enable by setting ENABLE_FILE_LINKS=True
             )
             (?=                            # URL must be followed by (not included in group)
                 [!:;\?\),\.\'\"\>]*         # Optional punctuation characters
                 (?:\Z|\s)                  # followed by whitespace or end of string
             )
-            """ % (tlds, nested_paren_chunk)
+            """ % (tlds, nested_paren_chunk,
+                   r"| (?:file://(/[^/ ]*)+/?)" if settings.ENABLE_FILE_LINKS else r"")
         md.inlinePatterns.add('autolink', AutoLink(link_regex), '>link')
 
         md.preprocessors.add('hanging_ulists',

zerver/models.py

@@ -925,7 +925,10 @@ class Message(ModelReprMixin, models.Model):
     @staticmethod
     def content_has_link(content):
         # type: (text_type) -> bool
-        return 'http://' in content or 'https://' in content or '/user_uploads' in content
+        return ('http://' in content or
+                'https://' in content or
+                '/user_uploads' in content or
+                (settings.ENABLE_FILE_LINKS and 'file:///' in content))
 
     @staticmethod
     def is_status_message(content, rendered_content):

zerver/tests/test_bugdown.py

@@ -211,6 +211,22 @@ class BugdownTest(TestCase):
             converted = bugdown_convert(inline_url)
             self.assertEqual(match, converted)
 
+    def test_inline_file(self):
+        # type: () -> None
+        msg = 'Check out this file file:///Volumes/myserver/Users/Shared/pi.py'
+        converted = bugdown_convert(msg)
+        self.assertEqual(converted, '<p>Check out this file <a href="file:///Volumes/myserver/Users/Shared/pi.py" target="_blank" title="file:///Volumes/myserver/Users/Shared/pi.py">file:///Volumes/myserver/Users/Shared/pi.py</a></p>')
+
+        with self.settings(ENABLE_FILE_LINKS=False):
+            realm = Realm.objects.create(
+                domain='file_links_test.example.com',
+                string_id='file_links_test')
+            bugdown.make_md_engine(
+                realm.domain,
+                {'realm_filters': [[], u'file_links_test.example.com'], 'realm': [u'file_links_test.example.com', 'Realm name']})
+            converted = bugdown.convert(msg, realm_domain=realm.domain)
+            self.assertEqual(converted, '<p>Check out this file file:///Volumes/myserver/Users/Shared/pi.py</p>')
+
     def test_inline_youtube(self):
         # type: () -> None
         msg = 'Check out the debate: http://www.youtube.com/watch?v=hx1mjT73xYE'

zproject/prod_settings_template.py

@@ -140,6 +140,10 @@ ERROR_REPORTING = True
 # a link to an image is referenced in a message.
 INLINE_IMAGE_PREVIEW = True
 
+# Controls whether or not Zulip will parse links starting with
+# "file:///" as a hyperlink (useful if you have e.g. an NFS share).
+ENABLE_FILE_LINKS = False
+
 # By default, files uploaded by users and user avatars are stored
 # directly on the Zulip server.  If file storage in Amazon S3 is
 # desired, you can configure that as follows:

zproject/settings.py

@@ -179,6 +179,7 @@ DEFAULT_SETTINGS = {'TWITTER_CONSUMER_KEY': '',
                     'FIRST_TIME_TOS_TEMPLATE': None,
                     'USING_PGROONGA': False,
                     'POST_MIGRATION_CACHE_FLUSHING': False,
+                    'ENABLE_FILE_LINKS': False,
                     }
 
 for setting_name, setting_val in six.iteritems(DEFAULT_SETTINGS):

zproject/test_settings.py

@@ -91,6 +91,9 @@ CACHES['database'] = {
     }
 }
 
+# Enable file:/// hyperlink support by default in tests
+ENABLE_FILE_LINKS = True
+
 LOGGING['loggers']['zulip.requests']['level'] = 'CRITICAL'
 LOGGING['loggers']['zulip.management']['level'] = 'CRITICAL'