Additional fix for mismatching variable names: regression from ruby-g…

…rape#1263, closes ruby-grape#1307.

lib/grape/api.rb

@@ -131,8 +131,9 @@ def add_head_not_allowed_methods_and_options_methods
       self.class.endpoints.each do |endpoint|
         routes = endpoint.routes
         routes.each do |route|
-          # ignore any optional portions of the path
-          route_path = route.route_path.gsub(/\(.*\)/, '')
+          route_path = route.route_path
+                       .gsub(/\(.*\)/, '') # ignore any optional portions
+                       .gsub(%r{\:[^\/.?]+}, ':x') # substitute variable names to avoid conflicts
 
           methods_per_path[route_path] ||= []
           methods_per_path[route_path] << route.route_method

spec/grape/api/required_parameters_in_route_spec.rb

@@ -0,0 +1,37 @@
+require 'spec_helper'
+
+describe Grape::Endpoint do
+  subject { Class.new(Grape::API) }
+
+  def app
+    subject
+  end
+
+  before do
+    subject.namespace :api do
+      get ':id' do
+        [params[:id], params[:ext]].compact.join('/')
+      end
+
+      put ':something_id' do
+        params[:something_id]
+      end
+    end
+  end
+
+  context 'get' do
+    it 'responds' do
+      get '/api/foo'
+      expect(last_response.status).to eq 200
+      expect(last_response.body).to eq 'foo'
+    end
+  end
+
+  context 'put' do
+    it 'responds' do
+      put '/api/foo'
+      expect(last_response.status).to eq 200
+      expect(last_response.body).to eq 'foo'
+    end
+  end
+end