Improve exception handling when Location header is invalid. [#1192 state:resolved]

Signed-off-by: Pratik Naik <pratiknaik@gmail.com>

activeresource/lib/active_resource/base.rb

@@ -1006,7 +1006,7 @@ def load_attributes_from_response(response)
 
       # Takes a response from a typical create post and pulls the ID out
       def id_from_response(response)
-        response['Location'][/\/([^\/]*?)(\.\w+)?$/, 1]
+        response['Location'][/\/([^\/]*?)(\.\w+)?$/, 1] if response['Location']
       end
 
       def element_path(options = nil)

activeresource/test/base_test.rb

@@ -627,6 +627,12 @@ def test_id_from_response
     assert_equal '1', p.__send__(:id_from_response, resp)
   end
 
+  def test_id_from_response_without_location
+    p = Person.new
+    resp = {}
+    assert_equal nil, p.__send__(:id_from_response, resp)
+  end
+
   def test_create_with_custom_prefix
     matzs_house = StreetAddress.new(:person_id => 1)
     matzs_house.save
@@ -670,7 +676,6 @@ def test_reload_works_without_prefix_options
     assert_equal person, person.reload
   end
 
-
   def test_create
     rick = Person.create(:name => 'Rick')
     assert rick.valid?
@@ -687,6 +692,14 @@ def test_create
     assert_raises(ActiveResource::ResourceConflict) { Person.create(:name => 'Rick') }
   end
 
+  def test_create_without_location
+    ActiveResource::HttpMock.respond_to do |mock|
+      mock.post   "/people.xml", {}, nil, 201
+    end
+    person = Person.create(:name => 'Rick')
+    assert_equal nil, person.id
+  end
+
   def test_clone
     matz = Person.find(1)
     matz_c = matz.clone