1 files changed, 9 insertions, 6 deletions
diff --git a/actionpack/lib/action_view/lookup_context.rb b/actionpack/lib/action_view/lookup_context.rb
index 06c607931d..f0ed3425de 100644
--- a/actionpack/lib/action_view/lookup_context.rb
+++ b/actionpack/lib/action_view/lookup_context.rb
@@ -9,6 +9,8 @@ module ActionView
   # generate a key, given to view paths, used in the resolver cache lookup. Since
   # this key is generated just once during the request, it speeds up all cache accesses.
   class LookupContext #:nodoc:
+    attr_accessor :prefixes
+    
     mattr_accessor :fallbacks
     @@fallbacks = FallbackFileSystemResolver.instances
 
@@ -58,10 +60,11 @@ module ActionView
       end
     end
 
-    def initialize(view_paths, details = {})
+    def initialize(view_paths, details = {}, prefixes = [])
       @details, @details_key = { :handlers => default_handlers }, nil
       @frozen_formats, @skip_default_locale = false, false
       @cache = true
+      @prefixes = prefixes
 
       self.view_paths = view_paths
       self.registered_detail_setters.each do |key, setter|
@@ -164,12 +167,12 @@ module ActionView
         @frozen_formats = true
       end
 
-      # Overload formats= to reject ["*/*"] values.
+      # Overload formats= to expand ["*/*"] values and automatically
+      # add :html as fallback to :js.
       def formats=(values)
-        if values && values.size == 1
-          value = values.first
-          values = nil    if value == "*/*"
-          values << :html if value == :js
+        if values
+          values.concat(_formats_defaults) if values.delete "*/*"
+          values << :html if values == [:js]
         end
         super(values)
       end