events: make the System URL extraction safer.

Prevents any possible errors inside events.

rhodecode/events/base.py

@@ -15,6 +15,7 b''
 # This program is dual-licensed. If you wish to learn more about the
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
+import logging
 
 from datetime import datetime
 from pyramid.threadlocal import get_current_request
@@ -26,6 +27,8 b' SYSTEM_USER = AttributeDict(dict('
     username='__SYSTEM__'
 ))
 
+log = logging.getLogger(__name__)
+
 
 class RhodecodeEvent(object):
     """
@@ -66,10 +69,16 b' class RhodecodeEvent(object):'
 
     @property
     def server_url(self):
+        default = '<no server_url available>'
         if self.request:
             from rhodecode.lib import helpers as h
+            try:
             return h.url('home', qualified=True)
-        return '<no server_url available>'
+            except Exception:
+                log.exception('Failed to fetch URL for server')
+                return default
+
+        return default
 
     def as_dict(self):
         data = {

rhodecode/events/pullrequest.py

@@ -16,11 +16,14 b''
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
+import logging
 
 from rhodecode.translation import lazy_ugettext
 from rhodecode.events.repo import (
     RepoEvent, _commits_as_dict, _issues_as_dict)
 
+log = logging.getLogger(__name__)
+
 
 class PullRequestEvent(RepoEvent):
     """

rhodecode/events/user.py

@@ -15,6 +15,7 b''
 # This program is dual-licensed. If you wish to learn more about the
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
+import logging
 
 from zope.interface import implementer
 
@@ -23,6 +24,8 b' from rhodecode.events.base import Rhodec'
 from rhodecode.events.interfaces import (
     IUserRegistered, IUserPreCreate, IUserPreUpdate)
 
+log = logging.getLogger(__name__)
+
 
 @implementer(IUserRegistered)
 class UserRegistered(RhodecodeEvent):