1 files changed, 47 insertions, 24 deletions

diff --git a/activesupport/lib/active_support/dependencies.rb b/activesupport/lib/active_support/dependencies.rb
index 6be19771f5..e03e7c30d8 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
@@ -180,13 +184,14 @@ module ActiveSupport #:nodoc:
         Dependencies.load_missing_constant(from_mod, const_name)
       end
 
-      # Dependencies assumes the name of the module reflects the nesting (unless
-      # it can be proven that is not the case), and the path to the file that
-      # defines the constant. Anonymous modules cannot follow these conventions
-      # and we assume therefore the user wants to refer to a top-level constant.
+      # We assume that the name of the module reflects the nesting
+      # (unless it can be proven that is not the case) and the path to the file
+      # that defines the constant. Anonymous modules cannot follow these
+      # conventions and therefore we assume that the user wants to refer to a
+      # 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
@@ -200,7 +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)
@@ -236,18 +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.
       #
@@ -264,6 +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.
@@ -316,6 +326,7 @@ module ActiveSupport #:nodoc:
     def clear
       log_call
       loaded.clear
+      loading.clear
       remove_unloadable_constants!
     end
 
@@ -328,6 +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?
@@ -350,6 +362,8 @@ module ActiveSupport #:nodoc:
       rescue Exception
         loaded.delete expanded
         raise
+      ensure
+        loading.pop
       end
 
       # Record history *after* loading so first load gets warnings.
@@ -407,7 +421,8 @@ module ActiveSupport #:nodoc:
     end
 
     def load_once_path?(path)
-      # to_s works around a ruby1.9 issue where #starts_with?(Pathname) will always return false
+      # 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
 
@@ -473,7 +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)
@@ -514,9 +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
@@ -665,6 +680,14 @@ module ActiveSupport #:nodoc:
       constants = normalized.split('::')
       to_remove = constants.pop
 
+      # Remove the file path from the loaded list.
+      file_path = search_for_file(const.underscore)
+      if file_path
+        expanded = File.expand_path(file_path)
+        expanded.sub!(/\.rb\z/, '')
+        self.loaded.delete(expanded)
+      end
+
       if constants.empty?
         parent = Object
       else
@@ -719,7 +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})"