Fix a false positive for Style/ArgumentsForwarding

changelog/fix_a_false_positive_for_style_arguments_forwarding.md

@@ -0,0 +1 @@
+* [#12626](https://github.com/rubocop/rubocop/pull/12626): Fix a false positive for `Style/ArgumentsForwarding` when naming a block argument `&`. ([@koic][])

lib/rubocop/cop/style/arguments_forwarding.rb

@@ -291,7 +291,7 @@ def register_forward_kwargs_offense(add_parens, def_arguments_or_send, kwrest_ar
         end
 
         def register_forward_block_arg_offense(add_parens, def_arguments_or_send, block_arg)
-          return if target_ruby_version <= 3.0
+          return if target_ruby_version <= 3.0 || block_arg.source == '&'
 
           add_offense(block_arg, message: BLOCK_MSG) do |corrector|
             add_parens_if_missing(def_arguments_or_send, corrector) if add_parens

spec/rubocop/cop/style/arguments_forwarding_spec.rb

@@ -197,6 +197,14 @@ def foo(&)
       RUBY
     end
 
+    it 'does not register an offense when naming block arg `&`', :ruby31 do
+      expect_no_offenses(<<~RUBY)
+        def foo(&)
+          bar(&)
+        end
+      RUBY
+    end
+
     context 'when `RedundantBlockArgumentNames: [meaningless_block_name]`' do
       let(:redundant_block_argument_names) { ['meaningless_block_name'] }