handle time zones more robustly

user time zone of '' was freaking out production

Author: azul

app/controllers/common/application/before_filters.rb

@@ -106,7 +106,10 @@ def set_session_locale
   # set the current timezone, if the user has it configured.
   #
   def set_session_timezone
-    Time.zone = current_user.time_zone if logged_in?
+    Time.zone = current_user.time_zone
+  rescue ArgumentError # invalid string
+    Rails.logger.warn "Invalid time zone #{current_user.time_zone} for user #{current_user.login}"
+    Time.zone = Time.zone_default
   end
 
   #

app/models/unauthenticated_user.rb

@@ -60,4 +60,8 @@ def real?
     false
   end
 
+  def time_zone
+    Time.zone_default
+  end
+
 end

app/models/user.rb

@@ -171,7 +171,7 @@ def online?
   end
 
   def time_zone
-    read_attribute(:time_zone) || Time.zone_default
+    read_attribute(:time_zone).presence || Time.zone_default
   end
 
   #