14 files changed, 55 insertions, 40 deletions
diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index b9b771b930..58af62ee76 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -1,3 +1,10 @@
+*   Show helpful message in `BadRequest` exceptions due to invalid path
+    parameter encodings.
+
+    Fixes #21923.
+
+    *Agis Anastasopoulos*
+
 *   Deprecate `config.static_cache_control` in favor of
     `config.public_file_server.headers`
 
diff --git a/actionpack/lib/action_controller/metal/exceptions.rb b/actionpack/lib/action_controller/metal/exceptions.rb
index 18e003741d..5260dc0336 100644
--- a/actionpack/lib/action_controller/metal/exceptions.rb
+++ b/actionpack/lib/action_controller/metal/exceptions.rb
@@ -5,12 +5,10 @@ module ActionController
   class BadRequest < ActionControllerError #:nodoc:
     attr_reader :original_exception
 
-    def initialize(type = nil, e = nil)
-      return super() unless type && e
-
-      super("Invalid #{type} parameters: #{e.message}")
+    def initialize(msg = nil, e = nil)
+      super(msg)
       @original_exception = e
-      set_backtrace e.backtrace
+      set_backtrace e.backtrace if e
     end
   end
 
diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index bf20a33d36..c6ab4dbc9a 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -65,7 +65,7 @@ module ActionDispatch
       path_parameters.each do |key, value|
         next unless value.respond_to?(:valid_encoding?)
         unless value.valid_encoding?
-          raise ActionController::BadRequest, "Invalid parameter: #{key} => #{value}"
+          raise ActionController::BadRequest, "Invalid parameter encoding: #{key} => #{value.inspect}"
         end
       end
     end
@@ -341,7 +341,7 @@ module ActionDispatch
         set_header k, Request::Utils.normalize_encode_params(super || {})
       end
     rescue Rack::Utils::ParameterTypeError, Rack::Utils::InvalidParameterError => e
-      raise ActionController::BadRequest.new(:query, e)
+      raise ActionController::BadRequest.new("Invalid query parameters: #{e.message}", e)
     end
     alias :query_parameters :GET
 
@@ -357,7 +357,7 @@ module ActionDispatch
       self.request_parameters = Request::Utils.normalize_encode_params(super || {})
       raise
     rescue Rack::Utils::ParameterTypeError, Rack::Utils::InvalidParameterError => e
-      raise ActionController::BadRequest.new(:request, e)
+      raise ActionController::BadRequest.new("Invalid request parameters: #{e.message}", e)
     end
     alias :request_parameters :POST
 
diff --git a/actionpack/test/dispatch/request_test.rb b/actionpack/test/dispatch/request_test.rb
index af2ed24f43..dfedc8ae25 100644
--- a/actionpack/test/dispatch/request_test.rb
+++ b/actionpack/test/dispatch/request_test.rb
@@ -961,6 +961,20 @@ class RequestParameters < BaseRequestTest
     end
   end
 
+  test "path parameters with invalid UTF8 encoding" do
+    request = stub_request(
+      "action_dispatch.request.path_parameters" => { foo: "\xBE" }
+    )
+
+    err = assert_raises(ActionController::BadRequest) do
+      request.check_path_parameters!
+    end
+
+    assert_match "Invalid parameter encoding", err.message
+    assert_match "foo", err.message
+    assert_match "\\xBE", err.message
+  end
+
   test "parameters not accessible after rack parse error of invalid UTF8 character" do
     request = stub_request("QUERY_STRING" => "foo%81E=1")
 
diff --git a/activerecord/lib/active_record/relation/where_clause_factory.rb b/activerecord/lib/active_record/relation/where_clause_factory.rb
index 9662756c2e..a81ff98e49 100644
--- a/activerecord/lib/active_record/relation/where_clause_factory.rb
+++ b/activerecord/lib/active_record/relation/where_clause_factory.rb
@@ -20,6 +20,8 @@ module ActiveRecord
           attributes, binds = predicate_builder.create_binds(attributes)
 
           parts = predicate_builder.build_from_hash(attributes)
+        when Arel::Nodes::Node
+          parts = [opts]
         else
           raise ArgumentError, "Unsupported argument type: #{opts} (#{opts.class})"
         end
diff --git a/activerecord/test/cases/relation/where_test.rb b/activerecord/test/cases/relation/where_test.rb
index 399a4dbbf1..bc6378b90e 100644
--- a/activerecord/test/cases/relation/where_test.rb
+++ b/activerecord/test/cases/relation/where_test.rb
@@ -304,8 +304,6 @@ module ActiveRecord
     end
 
     def test_where_with_unsupported_arguments
-      author = authors(:david)
-
       assert_raises(ArgumentError) { Author.where(42) }
     end
   end
diff --git a/activerecord/test/cases/relation_test.rb b/activerecord/test/cases/relation_test.rb
index b0fb905760..675149556f 100644
--- a/activerecord/test/cases/relation_test.rb
+++ b/activerecord/test/cases/relation_test.rb
@@ -57,9 +57,6 @@ module ActiveRecord
     def test_empty_where_values_hash
       relation = Relation.new(FakeKlass, :b, nil)
       assert_equal({}, relation.where_values_hash)
-
-      relation.where! :hello
-      assert_equal({}, relation.where_values_hash)
     end
 
     def test_has_values
@@ -153,10 +150,10 @@ module ActiveRecord
     end
 
     test 'merging a hash into a relation' do
-      relation = Relation.new(FakeKlass, :b, nil)
-      relation = relation.merge where: :lol, readonly: true
+      relation = Relation.new(Post, Post.arel_table, Post.predicate_builder)
+      relation = relation.merge where: {name: :lol}, readonly: true
 
-      assert_equal Relation::WhereClause.new([:lol], []), relation.where_clause
+      assert_equal({"name"=>:lol}, relation.where_clause.to_h)
       assert_equal true, relation.readonly_value
     end
 
@@ -185,7 +182,7 @@ module ActiveRecord
     end
 
     test '#values returns a dup of the values' do
-      relation = Relation.new(FakeKlass, :b, nil).where! :foo
+      relation = Relation.new(Post, Post.arel_table, Post.predicate_builder).where!(name: :foo)
       values   = relation.values
 
       values[:where] = nil
diff --git a/activesupport/lib/active_support/railtie.rb b/activesupport/lib/active_support/railtie.rb
index cd0fb51009..845788b669 100644
--- a/activesupport/lib/active_support/railtie.rb
+++ b/activesupport/lib/active_support/railtie.rb
@@ -26,7 +26,7 @@ module ActiveSupport
 
       unless zone_default
         raise 'Value assigned to config.time_zone not recognized. ' \
-          'Run "rake -D time" for a list of tasks for finding appropriate time zone names.'
+          'Run "rake time:zones:all" for a time zone names list.'
       end
 
       Time.zone_default = zone_default
diff --git a/activesupport/lib/active_support/values/time_zone.rb b/activesupport/lib/active_support/values/time_zone.rb
index 681f659100..9f4bb6762d 100644
--- a/activesupport/lib/active_support/values/time_zone.rb
+++ b/activesupport/lib/active_support/values/time_zone.rb
@@ -26,12 +26,6 @@ module ActiveSupport
   #   Time.zone      # => #<ActiveSupport::TimeZone:0x514834...>
   #   Time.zone.name # => "Eastern Time (US & Canada)"
   #   Time.zone.now  # => Sun, 18 May 2008 14:30:44 EDT -04:00
-  #
-  # The version of TZInfo bundled with Active Support only includes the
-  # definitions necessary to support the zones defined by the TimeZone class.
-  # If you need to use zones that aren't defined by TimeZone, you'll need to
-  # install the TZInfo gem (if a recent version of the gem is installed locally,
-  # this will be used instead of the bundled version.)
   class TimeZone
     # Keys are Rails TimeZone names, values are TZInfo identifiers.
     MAPPING = {
diff --git a/guides/source/active_job_basics.md b/guides/source/active_job_basics.md
index 17087d187a..a114686f0f 100644
--- a/guides/source/active_job_basics.md
+++ b/guides/source/active_job_basics.md
@@ -136,10 +136,19 @@ module YourApp
 end
 ```
 
-NOTE: Since jobs run in parallel to your Rails application, most queuing libraries
+### Starting the Backend
+
+Since jobs run in parallel to your Rails application, most queuing libraries
 require that you start a library-specific queuing service (in addition to
-starting your Rails app) for the job processing to work. For information on
-how to do that refer to the documentation of your respective library.
+starting your Rails app) for the job processing to work. Refer to library
+documentation for instructions on starting your queue backend.
+
+Here is a noncomprehensive list of documentation:
+
+- [Sidekiq](https://github.com/mperham/sidekiq/wiki/Active-Job)
+- [Resque](https://github.com/resque/resque/wiki/ActiveJob)
+- [Sucker Punch](https://github.com/brandonhilkert/sucker_punch#active-job)
+- [Queue Classic](https://github.com/QueueClassic/queue_classic#active-job)
 
 Queues
 ------
diff --git a/guides/source/active_model_basics.md b/guides/source/active_model_basics.md
index 2bdbd792a8..fe2501bd87 100644
--- a/guides/source/active_model_basics.md
+++ b/guides/source/active_model_basics.md
@@ -197,7 +197,7 @@ person.last_name_change # => nil
 
 ### Validations
 
-`ActiveModel::Validations` module adds the ability to validate class objects
+The `ActiveModel::Validations` module adds the ability to validate class objects
 like in Active Record.
 
 ```ruby
@@ -292,7 +292,7 @@ objects.
 
 ### Serialization
 
-`ActiveModel::Serialization` provides a basic serialization for your object.
+`ActiveModel::Serialization` provides basic serialization for your object.
 You need to declare an attributes hash which contains the attributes you want to
 serialize. Attributes must be strings, not symbols.
 
@@ -339,7 +339,7 @@ class Person
 end
 ```
 
-With the `as_json` you have a hash representing the model.
+With the `as_json` method you have a hash representing the model.
 
 ```ruby
 person = Person.new
@@ -408,7 +408,7 @@ Person.human_attribute_name('name') # => "Nome"
 
 ### Lint Tests
 
-`ActiveModel::Lint::Tests` allow you to test whether an object is compliant with
+`ActiveModel::Lint::Tests` allows you to test whether an object is compliant with
 the Active Model API.
 
 * app/models/person.rb
@@ -461,14 +461,14 @@ an accessor named `password` with certain validations on it.
 
 #### Requirements
 
-`ActiveModel::SecurePassword` depends on the [`bcrypt`](https://github.com/codahale/bcrypt-ruby 'BCrypt'),
+`ActiveModel::SecurePassword` depends on [`bcrypt`](https://github.com/codahale/bcrypt-ruby 'BCrypt'),
 so include this gem in your Gemfile to use `ActiveModel::SecurePassword` correctly.
 In order to make this work, the model must have an accessor named `password_digest`.
 The `has_secure_password` will add the following validations on the `password` accessor:
 
 1. Password should be present.
 2. Password should be equal to its confirmation.
-3. This maximum length of a password is 72 (required by `bcrypt` on which ActiveModel::SecurePassword depends)
+3. The maximum length of a password is 72 (required by `bcrypt` on which ActiveModel::SecurePassword depends)
 
 #### Examples
 
@@ -489,7 +489,7 @@ person.password = 'aditya'
 person.password_confirmation = 'nomatch'
 person.valid? # => false
 
-# When the length of password, exceeds 72.
+# When the length of password exceeds 72.
 person.password = person.password_confirmation = 'a' * 100
 person.valid? # => false
 
diff --git a/guides/source/engines.md b/guides/source/engines.md
index 71844b7990..f961b799f1 100644
--- a/guides/source/engines.md
+++ b/guides/source/engines.md
@@ -670,7 +670,7 @@ pre-defined path which may be customizable.
 The engine contains migrations for the `blorgh_articles` and `blorgh_comments`
 table which need to be created in the application's database so that the
 engine's models can query them correctly. To copy these migrations into the
-application use this command:
+application run the following command from the `test/dummy` directory of your Rails engine:
 
 ```bash
 $ rake blorgh:install:migrations
diff --git a/railties/lib/rails/generators/rails/app/templates/config/application.rb b/railties/lib/rails/generators/rails/app/templates/config/application.rb
index 6b7d7abd0b..ddd0fcade1 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/application.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/application.rb
@@ -26,7 +26,7 @@ module <%= app_const_base %>
     # -- all .rb files in that directory are automatically loaded.
 
     # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
-    # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
+    # Run "rake time:zones:all" for a time zone names list. Default is UTC.
     # config.time_zone = 'Central Time (US & Canada)'
 
     # The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
diff --git a/railties/lib/rails/generators/rails/plugin/plugin_generator.rb b/railties/lib/rails/generators/rails/plugin/plugin_generator.rb
index 81bc902bde..c65b8b84be 100644
--- a/railties/lib/rails/generators/rails/plugin/plugin_generator.rb
+++ b/railties/lib/rails/generators/rails/plugin/plugin_generator.rb
@@ -237,10 +237,6 @@ task default: :test
         build(:javascripts) unless api?
       end
 
-      def create_images_directory
-        build(:images) unless api?
-      end
-
       def create_bin_files
         build(:bin)
       end