Fix type error if there is a different location hash

app/assets/javascripts/tree.js.coffee

@@ -40,12 +40,12 @@ $ ->
   # "#L12" and "#L34-56" supported
   highlightBlobLines = ->
     if window.location.hash isnt ""
-      matches = window.location.hash.match /\#L(\d+)(\-(\d+))?/
-      first_line = parseInt matches[1]
-      last_line = parseInt matches[3]
+      matches = window.location.hash.match(/\#L(\d+)(\-(\d+))?/)
+      first_line = parseInt(matches?[1])
+      last_line = parseInt(matches?[3])
 
       unless isNaN first_line
-        last_line = first_line if isNaN last_line
+        last_line = first_line if isNaN(last_line)
         $("#tree-content-holder .highlight .line").removeClass("hll")
         $("#LC#{line}").addClass("hll") for line in [first_line..last_line]
         $("#L#{first_line}").ScrollTo()