Fix crash on active view being a HtmlSheet (#155)

Author: rchl

README.md

@@ -24,7 +24,7 @@ A [Sublime Text](http://www.sublimetext.com) plugin that allows you to…
 	- [Trim On Save](#trim-on-save)
 	- [Save After Trim](#save-after-trim)
 	- [Live Matching vs On-demand Matching](#live-matching-vs-on-demand-matching)
-	- [Ignore Syntax](#ignore-syntax)
+	- [Ignore Scope](#ignore-scope)
 	- [For power-users only!](#for-power-users-only)
 		- [Disabled for large files](#disabled-for-large-files)
 		- [The matching pattern](#the-matching-pattern)

trailing_spaces.py

@@ -491,7 +491,10 @@ def is_view_visible(self, view):
         # see if this view is visible in its group
         group = window.get_view_index(view)[0]
         if group != -1:
-            return view.id() == window.active_view_in_group(group).id()
+            active_view_in_group = window.active_view_in_group(group)
+            # won't be present if a html sheet is active
+            if active_view_in_group:
+                return view.id() == active_view_in_group.id()
 
         # check if this view is the active panel
         active_panel = window.active_panel() or ""