[Fix rubocop#9713] Fix autocorrection for block local variables in `L…

…int/UnusedBlockArgument`

Closes rubocop#9713

changelog/fix_autocorrect_for_lint_unused_block_argument.md

@@ -0,0 +1 @@
+* [#9713](https://github.com/rubocop/rubocop/issues/9713): Fix autocorrection for block local variables in `Lint/UnusedBlockArgument`. ([@tejasbubane][])

lib/rubocop/cop/lint/unused_block_argument.rb

@@ -67,11 +67,17 @@ def autocorrect(corrector, node)
         end
 
         def check_argument(variable)
-          return if allowed_block?(variable) || allowed_keyword_argument?(variable)
+          return if allowed_block?(variable) ||
+                    allowed_keyword_argument?(variable) ||
+                    used_block_local?(variable)
 
           super
         end
 
+        def used_block_local?(variable)
+          variable.explicit_block_local_variable? && !variable.assignments.empty?
+        end
+
         def allowed_block?(variable)
           !variable.block_argument? || (ignore_empty_blocks? && empty_block?(variable))
         end

spec/rubocop/cop/lint/unused_block_argument_spec.rb

@@ -214,6 +214,17 @@
           RUBY
         end
       end
+
+      context 'and the variable is used' do
+        it 'does not register offense' do
+          expect_no_offenses(<<~RUBY)
+            1.times do |index; x|
+              x = 10
+              puts index
+            end
+          RUBY
+        end
+      end
     end
 
     context 'when a lambda block takes arguments' do