Routing: respond with 405 Method Not Allowed status when the route path matches but the HTTP method does not. Closes #6953.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6862 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 44 insertions, 7 deletions

diff --git a/actionpack/lib/action_controller/base.rb b/actionpack/lib/action_controller/base.rb
index dc5a1d18cd..8bff41d38d 100755
--- a/actionpack/lib/action_controller/base.rb
+++ b/actionpack/lib/action_controller/base.rb
@@ -22,6 +22,24 @@ module ActionController #:nodoc:
       @failures = failures
     end
   end
+  class MethodNotAllowed < ActionControllerError #:nodoc:
+    attr_reader :allowed_methods
+
+    def initialize(*allowed_methods)
+      super("Only #{allowed_methods.to_sentence} requests are allowed.")
+      @allowed_methods = allowed_methods
+    end
+
+    def allowed_methods_header
+      allowed_methods.map { |method_symbol| method_symbol.to_s.upcase } * ', '
+    end
+
+    def handle_response!(response)
+      response.headers['Allow'] ||= allowed_methods_header
+    end
+  end
+  class NotImplemented < MethodNotAllowed #:nodoc:
+  end
   class UnknownController < ActionControllerError #:nodoc:
   end
   class UnknownAction < ActionControllerError #:nodoc:
diff --git a/actionpack/lib/action_controller/rescue.rb b/actionpack/lib/action_controller/rescue.rb
index 225acd28f3..3ab10107bf 100644
--- a/actionpack/lib/action_controller/rescue.rb
+++ b/actionpack/lib/action_controller/rescue.rb
@@ -13,12 +13,14 @@ module ActionController #:nodoc:
 
     DEFAULT_RESCUE_RESPONSE = :internal_server_error
     DEFAULT_RESCUE_RESPONSES = {
-      'ActionController::RoutingError'    => :not_found,
-      'ActionController::UnknownAction'   => :not_found,
-      'ActiveRecord::RecordNotFound'      => :not_found,
-      'ActiveRecord::StaleObjectError'    => :conflict,
-      'ActiveRecord::RecordInvalid'       => :unprocessable_entity,
-      'ActiveRecord::RecordNotSaved'      => :unprocessable_entity
+      'ActionController::RoutingError'     => :not_found,
+      'ActionController::UnknownAction'    => :not_found,
+      'ActiveRecord::RecordNotFound'       => :not_found,
+      'ActiveRecord::StaleObjectError'     => :conflict,
+      'ActiveRecord::RecordInvalid'        => :unprocessable_entity,
+      'ActiveRecord::RecordNotSaved'       => :unprocessable_entity,
+      'ActionController::MethodNotAllowed' => :method_not_allowed,
+      'ActionController::NotImplemented'   => :not_implemented
     }
 
     DEFAULT_RESCUE_TEMPLATE = 'diagnostics'
@@ -56,6 +58,12 @@ module ActionController #:nodoc:
         log_error(exception) if logger
         erase_results if performed?
 
+        # Let the exception alter the response if it wants.
+        # For example, MethodNotAllowed sets the Allow header.
+        if exception.respond_to?(:handle_response!)
+          exception.handle_response!(response)
+        end
+
         if consider_all_requests_local || local_request?
           rescue_action_locally(exception)
         else
diff --git a/actionpack/lib/action_controller/routing.rb b/actionpack/lib/action_controller/routing.rb
index 00d5050b7e..4a1eda82bf 100644
--- a/actionpack/lib/action_controller/routing.rb
+++ b/actionpack/lib/action_controller/routing.rb
@@ -251,6 +251,8 @@ module ActionController
     # TODO: , (comma) should be an allowed path character.
     SEPARATORS = %w( / ; . , ? )
 
+    HTTP_METHODS = [:get, :head, :post, :put, :delete]
+
     # The root paths which may contain controller files
     mattr_accessor :controller_paths
     self.controller_paths = []
@@ -1345,7 +1347,16 @@ module ActionController
         routes.each do |route|
           result = route.recognize(path, environment) and return result
         end
-        raise RoutingError, "no route found to match #{path.inspect} with #{environment.inspect}"
+
+        allows = HTTP_METHODS.select { |verb| routes.find { |r| r.recognize(path, :method => verb) } }
+
+        if environment[:method] && !HTTP_METHODS.include?(environment[:method])
+          raise NotImplemented.new(*allows)
+        elsif !allows.empty?
+          raise MethodNotAllowed.new(*allows)
+        else
+          raise RoutingError, "No route matches #{path.inspect} with #{environment.inspect}"
+        end
       end
   
       def routes_by_controller