Eliminate Pathname extensions

activesupport/lib/active_support/core_ext/exception.rb

-require 'active_support/core_ext/pathname'
-
 module ActiveSupport
   FrozenObjectError = RUBY_VERSION < '1.9' ? TypeError : RuntimeError
 end
 
 # TODO: Turn all this into using the BacktraceCleaner.
 class Exception # :nodoc:
+  # Clean the paths contained in the message.
+  def self.clean_paths(string)
+    require 'pathname' unless defined? Pathname
+    string.gsub(%r{[\w. ]+(/[\w. ]+)+(\.rb)?(\b|$)}) do |path|
+      Pathname.new(path).cleanpath
+    end
+  end
+
   def clean_message
-    Pathname.clean_within message
+    Exception.clean_paths(message)
   end
 
   TraceSubstitutions = []
@@ -16,9 +22,10 @@ def clean_message
 
   def clean_backtrace
     backtrace.collect do |line|
-      Pathname.clean_within(TraceSubstitutions.inject(line) do |result, (regexp, sub)|
+      substituted = TraceSubstitutions.inject(line) do |result, (regexp, sub)|
         result.gsub regexp, sub
-      end)
+      end
+      Exception.clean_paths(substituted)
     end
   end
 

activesupport/lib/active_support/core_ext/pathname.rb

-if defined? Pathname
-  require 'active_support/core_ext/pathname/clean_within'
-else
-  autoload :Pathname, 'active_support/core_ext/pathname/clean_within'
-end

activesupport/lib/active_support/core_ext/pathname/clean_within.rb

-require 'pathname'
-
-class Pathname
-  # Clean the paths contained in the provided string.
-  def self.clean_within(string)
-    string.gsub(%r{[\w. ]+(/[\w. ]+)+(\.rb)?(\b|$)}) do |path|
-      new(path).cleanpath
-    end
-  end
-end

activesupport/test/core_ext/pathname_test.rb

-require 'abstract_unit'
-require 'active_support/core_ext/pathname'
-
-class TestPathname < Test::Unit::TestCase
-  def test_clean_within
-    assert_equal "Hi", Pathname.clean_within("Hi")
-    assert_equal "Hi", Pathname.clean_within("Hi/a/b/../..")
-    assert_equal "Hello\nWorld", Pathname.clean_within("Hello/a/b/../..\na/b/../../World/c/..")
-  end
-end