4 files changed, 64 insertions, 4 deletions
diff --git a/activesupport/lib/active_support/backtrace_cleaner.rb b/activesupport/lib/active_support/backtrace_cleaner.rb
index 16dd733ddb..1796956bd7 100644
--- a/activesupport/lib/active_support/backtrace_cleaner.rb
+++ b/activesupport/lib/active_support/backtrace_cleaner.rb
@@ -31,6 +31,9 @@ module ActiveSupport
   class BacktraceCleaner
     def initialize
       @filters, @silencers = [], []
+      add_gem_filter
+      add_gem_silencer
+      add_stdlib_silencer
     end
 
     # Returns the backtrace after all filters and silencers have been run
@@ -82,6 +85,26 @@ module ActiveSupport
     end
 
     private
+
+      FORMATTED_GEMS_PATTERN = /\A[^\/]+ \([\w.]+\) /
+
+      def add_gem_filter
+        gems_paths = (Gem.path | [Gem.default_dir]).map { |p| Regexp.escape(p) }
+        return if gems_paths.empty?
+
+        gems_regexp = %r{(#{gems_paths.join('|')})/(bundler/)?gems/([^/]+)-([\w.]+)/(.*)}
+        gems_result = '\3 (\4) \5'.freeze
+        add_filter { |line| line.sub(gems_regexp, gems_result) }
+      end
+
+      def add_gem_silencer
+        add_silencer { |line| FORMATTED_GEMS_PATTERN.match?(line) }
+      end
+
+      def add_stdlib_silencer
+        add_silencer { |line| line.start_with?(RbConfig::CONFIG["rubylibdir"]) }
+      end
+
       def filter_backtrace(backtrace)
         @filters.each do |f|
           backtrace = backtrace.map { |line| f.call(line) }
diff --git a/activesupport/test/clean_backtrace_test.rb b/activesupport/test/clean_backtrace_test.rb
index 1b44c7c9bf..a0a7056952 100644
--- a/activesupport/test/clean_backtrace_test.rb
+++ b/activesupport/test/clean_backtrace_test.rb
@@ -74,3 +74,43 @@ class BacktraceCleanerFilterAndSilencerTest < ActiveSupport::TestCase
     assert_equal [ "/class.rb" ], @bc.clean([ "/mongrel/class.rb" ])
   end
 end
+
+class BacktraceCleanerDefaultFilterAndSilencerTest < ActiveSupport::TestCase
+  def setup
+    @bc = ActiveSupport::BacktraceCleaner.new
+  end
+
+  test "should format installed gems correctly" do
+    backtrace = [ "#{Gem.default_dir}/gems/nosuchgem-1.2.3/lib/foo.rb" ]
+    result = @bc.clean(backtrace, :all)
+    assert_equal "nosuchgem (1.2.3) lib/foo.rb", result[0]
+  end
+
+  test "should format installed gems not in Gem.default_dir correctly" do
+    target_dir = Gem.path.detect { |p| p != Gem.default_dir }
+    # skip this test if default_dir is the only directory on Gem.path
+    if target_dir
+      backtrace = [ "#{target_dir}/gems/nosuchgem-1.2.3/lib/foo.rb" ]
+      result = @bc.clean(backtrace, :all)
+      assert_equal "nosuchgem (1.2.3) lib/foo.rb", result[0]
+    end
+  end
+
+  test "should format gems installed by bundler" do
+    backtrace = [ "#{Gem.default_dir}/bundler/gems/nosuchgem-1.2.3/lib/foo.rb" ]
+    result = @bc.clean(backtrace, :all)
+    assert_equal "nosuchgem (1.2.3) lib/foo.rb", result[0]
+  end
+
+  test "should silence gems from the backtrace" do
+    backtrace = [ "#{Gem.path[0]}/gems/nosuchgem-1.2.3/lib/foo.rb" ]
+    result = @bc.clean(backtrace)
+    assert_empty result
+  end
+
+  test "should silence stdlib" do
+    backtrace = ["#{RbConfig::CONFIG["rubylibdir"]}/lib/foo.rb"]
+    result = @bc.clean(backtrace)
+    assert_empty result
+  end
+end
diff --git a/activesupport/test/core_ext/object/to_query_test.rb b/activesupport/test/core_ext/object/to_query_test.rb
index b0b7ef0913..561dadbbcf 100644
--- a/activesupport/test/core_ext/object/to_query_test.rb
+++ b/activesupport/test/core_ext/object/to_query_test.rb
@@ -88,7 +88,7 @@ class ToQueryTest < ActiveSupport::TestCase
     }
     expected = "foo[contents][][name]=gorby&foo[contents][][id]=123&foo[contents][][name]=puff&foo[contents][][d]=true"
 
-    assert_equal expected, URI.decode(params.to_query)
+    assert_equal expected, URI.decode_www_form_component(params.to_query)
   end
 
   private
diff --git a/activesupport/test/key_generator_test.rb b/activesupport/test/key_generator_test.rb
index cdde2c573a..9dfc0b2154 100644
--- a/activesupport/test/key_generator_test.rb
+++ b/activesupport/test/key_generator_test.rb
@@ -9,9 +9,6 @@ rescue LoadError, NameError
   $stderr.puts "Skipping KeyGenerator test: broken OpenSSL install"
 else
 
-  require "active_support/time"
-  require "active_support/json"
-
   class KeyGeneratorTest < ActiveSupport::TestCase
     def setup
       @secret    = SecureRandom.hex(64)