3 files changed, 7 insertions, 10 deletions
diff --git a/actionpack/lib/action_dispatch/http/mime_type.rb b/actionpack/lib/action_dispatch/http/mime_type.rb
index 95094c25c0..b64f660ec5 100644
--- a/actionpack/lib/action_dispatch/http/mime_type.rb
+++ b/actionpack/lib/action_dispatch/http/mime_type.rb
@@ -1,7 +1,6 @@
 require 'singleton'
 require 'active_support/core_ext/module/attribute_accessors'
 require 'active_support/core_ext/string/starts_ends_with'
-require 'active_support/deprecation'
 
 module Mime
   class Mimes
diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index bf20a33d36..35e3ac304f 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
@@ -338,10 +338,13 @@ module ActionDispatch
     # Override Rack's GET method to support indifferent access
     def GET
       fetch_header("action_dispatch.request.query_parameters") do |k|
-        set_header k, Request::Utils.normalize_encode_params(super || {})
+        rack_query_params = super || {}
+        # Check for non UTF-8 parameter values, which would cause errors later
+        Request::Utils.check_param_encoding(rack_query_params)
+        set_header k, Request::Utils.normalize_encode_params(rack_query_params)
       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 +360,7 @@ 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/lib/action_dispatch/http/response.rb b/actionpack/lib/action_dispatch/http/response.rb
index c54efb6541..f0127aa276 100644
--- a/actionpack/lib/action_dispatch/http/response.rb
+++ b/actionpack/lib/action_dispatch/http/response.rb
@@ -149,7 +149,6 @@ module ActionDispatch # :nodoc:
 
       self.body, self.status = body, status
 
-      @blank        = false
       @cv           = new_cond
       @committed    = false
       @sending      = false
@@ -287,12 +286,8 @@ module ActionDispatch # :nodoc:
       @stream.write string
     end
 
-    EMPTY = " "
-
     # Allows you to manually set or override the response body.
     def body=(body)
-      @blank = true if body == EMPTY
-
       if body.respond_to?(:to_path)
         @stream = body
       else