1 files changed, 35 insertions, 22 deletions

diff --git a/activesupport/lib/active_support/dependencies.rb b/activesupport/lib/active_support/dependencies.rb
index 8a545e4386..664cc15a29 100644
--- a/activesupport/lib/active_support/dependencies.rb
+++ b/activesupport/lib/active_support/dependencies.rb
@@ -30,6 +30,10 @@ module ActiveSupport #:nodoc:
     mattr_accessor :loaded
     self.loaded = Set.new
 
+    # Stack of files being loaded.
+    mattr_accessor :loading
+    self.loading = []
+
     # Should we load files or require them?
     mattr_accessor :mechanism
     self.mechanism = ENV['NO_RELOAD'] ? :require : :load
@@ -187,7 +191,7 @@ module ActiveSupport #:nodoc:
       # top-level constant.
       def guess_for_anonymous(const_name)
         if Object.const_defined?(const_name)
-          raise NameError, "#{const_name} cannot be autoloaded from an anonymous class or module"
+          raise NameError.new "#{const_name} cannot be autoloaded from an anonymous class or module", const_name
         else
           Object
         end
@@ -201,7 +205,10 @@ module ActiveSupport #:nodoc:
     # Object includes this module.
     module Loadable #:nodoc:
       def self.exclude_from(base)
-        base.class_eval { define_method(:load, Kernel.instance_method(:load)) }
+        base.class_eval do
+          define_method(:load, Kernel.instance_method(:load))
+          private :load
+        end
       end
 
       def require_or_load(file_name)
@@ -237,18 +244,6 @@ module ActiveSupport #:nodoc:
         raise
       end
 
-      def load(file, wrap = false)
-        result = false
-        load_dependency(file) { result = super }
-        result
-      end
-
-      def require(file)
-        result = false
-        load_dependency(file) { result = super }
-        result
-      end
-
       # Mark the given constant as unloadable. Unloadable constants are removed
       # each time dependencies are cleared.
       #
@@ -265,6 +260,20 @@ module ActiveSupport #:nodoc:
       def unloadable(const_desc)
         Dependencies.mark_for_unload const_desc
       end
+
+      private
+
+      def load(file, wrap = false)
+        result = false
+        load_dependency(file) { result = super }
+        result
+      end
+
+      def require(file)
+        result = false
+        load_dependency(file) { result = super }
+        result
+      end
     end
 
     # Exception file-blaming.
@@ -317,6 +326,7 @@ module ActiveSupport #:nodoc:
     def clear
       log_call
       loaded.clear
+      loading.clear
       remove_unloadable_constants!
     end
 
@@ -329,6 +339,7 @@ module ActiveSupport #:nodoc:
       # Record that we've seen this file *before* loading it to avoid an
       # infinite loop with mutual dependencies.
       loaded << expanded
+      loading << expanded
 
       begin
         if load?
@@ -351,6 +362,8 @@ module ActiveSupport #:nodoc:
       rescue Exception
         loaded.delete expanded
         raise
+      ensure
+        loading.pop
       end
 
       # Record history *after* loading so first load gets warnings.
@@ -360,7 +373,7 @@ module ActiveSupport #:nodoc:
 
     # Is the provided constant path defined?
     def qualified_const_defined?(path)
-      Object.qualified_const_defined?(path.sub(/^::/, ''), false)
+      Object.const_defined?(path, false)
     end
 
     # Given +path+, a filesystem path to a ruby file, return an array of
@@ -408,7 +421,7 @@ module ActiveSupport #:nodoc:
     end
 
     def load_once_path?(path)
-      # to_s works around a ruby1.9 issue where String#starts_with?(Pathname)
+      # to_s works around a ruby issue where String#starts_with?(Pathname)
       # will raise a TypeError: no implicit conversion of Pathname into String
       autoload_once_paths.any? { |base| path.starts_with? base.to_s }
     end
@@ -475,7 +488,7 @@ module ActiveSupport #:nodoc:
         expanded = File.expand_path(file_path)
         expanded.sub!(/\.rb\z/, '')
 
-        if loaded.include?(expanded)
+        if loading.include?(expanded)
           raise "Circular dependency detected while autoloading constant #{qualified_name}"
         else
           require_or_load(expanded, qualified_name)
@@ -516,9 +529,9 @@ module ActiveSupport #:nodoc:
         end
       end
 
-      raise NameError,
-            "uninitialized constant #{qualified_name}",
-            caller.reject { |l| l.starts_with? __FILE__ }
+      name_error = NameError.new("uninitialized constant #{qualified_name}", const_name)
+      name_error.set_backtrace(caller.reject {|l| l.starts_with? __FILE__ })
+      raise name_error
     end
 
     # Remove the constants that have been autoloaded, and those that have been
@@ -594,7 +607,7 @@ module ActiveSupport #:nodoc:
     def autoloaded?(desc)
       return false if desc.is_a?(Module) && desc.anonymous?
       name = to_constant_name desc
-      return false unless qualified_const_defined? name
+      return false unless qualified_const_defined?(name)
       return autoloaded_constants.include?(name)
     end
 
@@ -729,7 +742,7 @@ module ActiveSupport #:nodoc:
     protected
       def log_call(*args)
         if log_activity?
-          arg_str = args.collect { |arg| arg.inspect } * ', '
+          arg_str = args.collect(&:inspect) * ', '
           /in `([a-z_\?\!]+)'/ =~ caller(1).first
           selector = $1 || '<unknown>'
           log "called #{selector}(#{arg_str})"