Prefer remove_method over undef_method

Using `undef_method` means that when a route is removed any other
implementations of that method in the ancestor chain are inaccessible
so instead use `remove_method` which restores access to the ancestor.

2 files changed, 11 insertions, 4 deletions

diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index 73c30aa9b0..869fc7d484 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -1,3 +1,10 @@
+*   Prefer `remove_method` over `undef_method` when reloading routes
+
+    When `undef_method` is used it prevents access to other implementations of that
+    url helper in the ancestor chain so use `remove_method` instead to restores access.
+
+    *Andrew White*
+
 *   Add the `direct` method to the routing DSL
 
     This new method allows customization of the routing behavior in two ways:
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index 8bdf0d1a53..7cab421887 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -89,11 +89,11 @@ module ActionDispatch
 
         def clear!
           @path_helpers.each do |helper|
-            @path_helpers_module.send :undef_method, helper
+            @path_helpers_module.send :remove_method, helper
           end
 
           @url_helpers.each do |helper|
-            @url_helpers_module.send  :undef_method, helper
+            @url_helpers_module.send  :remove_method, helper
           end
 
           @custom_helpers.each do |helper|
@@ -101,11 +101,11 @@ module ActionDispatch
             url_name = :"#{helper}_url"
 
             if @path_helpers_module.method_defined?(path_name)
-              @path_helpers_module.send :undef_method, path_name
+              @path_helpers_module.send :remove_method, path_name
             end
 
             if @url_helpers_module.method_defined?(url_name)
-              @url_helpers_module.send :undef_method, url_name
+              @url_helpers_module.send :remove_method, url_name
             end
           end