Fix server mode live reload for C files (#1647)

## Summary

- The C parser didn't call `add_to_classes_or_modules` when creating
classes/modules, so `clear_file_contributions` couldn't clean up old
entries during server mode re-parse — causing duplicate methods when
editing C files with live reload.
- Add the call in both `find_class` and `handle_class_module`, matching
what the Ruby parsers already do.

Author: st0012

lib/rdoc/parser/c.rb

@@ -683,6 +683,7 @@ def find_class(raw_name, name, base_name = nil)
       container.name = base_name if base_name
 
       container.record_location @top_level
+      @top_level.add_to_classes_or_modules container
       @classes[raw_name] = container
     end
     @classes[raw_name]
@@ -898,6 +899,7 @@ def handle_class_module(var_name, type, class_name, parent, in_module)
     end
 
     cm.record_location enclosure.top_level
+    enclosure.top_level.add_to_classes_or_modules cm
 
     find_class_comment cm.full_name, cm
 

test/rdoc/parser/c_test.rb

@@ -2215,6 +2215,83 @@ def test_markup_format_override
     assert_equal("markdown", klass.attributes.find {|a| a.name == "default_format"}.comment.format)
   end
 
+  def test_clear_file_contributions_removes_c_methods
+    content = <<~C
+      /* Document-class: Foo */
+      VALUE cFoo = rb_define_class("Foo", rb_cObject);
+
+      /* call-seq: bar -> nil */
+      VALUE foo_bar(VALUE self) { return Qnil; }
+
+      void Init_Foo(void) {
+        cFoo = rb_define_class("Foo", rb_cObject);
+        rb_define_method(cFoo, "bar", foo_bar, 0);
+      }
+    C
+
+    util_get_class content, 'cFoo'
+
+    klass = @store.find_class_named 'Foo'
+    assert_equal 1, klass.method_list.size
+
+    @store.clear_file_contributions @top_level.relative_name
+    assert_equal 0, klass.method_list.size
+  end
+
+  def test_reparse_c_file_no_duplicates
+    content = <<~C
+      /* Document-class: Foo
+       * Original comment
+       */
+      VALUE cFoo = rb_define_class("Foo", rb_cObject);
+
+      /* call-seq: bar -> nil */
+      VALUE foo_bar(VALUE self) { return Qnil; }
+
+      void Init_Foo(void) {
+        cFoo = rb_define_class("Foo", rb_cObject);
+        rb_define_method(cFoo, "bar", foo_bar, 0);
+      }
+    C
+
+    # First parse
+    util_get_class content, 'cFoo'
+
+    klass = @store.find_class_named 'Foo'
+    assert_equal 1, klass.method_list.size
+
+    # Simulate server mode re-parse: clear then parse again
+    @store.clear_file_contributions @top_level.relative_name
+    @top_level.classes_or_modules.clear
+
+    updated_content = <<~C
+      /* Document-class: Foo
+       * Updated comment
+       */
+      VALUE cFoo = rb_define_class("Foo", rb_cObject);
+
+      /* call-seq: bar -> nil */
+      VALUE foo_bar(VALUE self) { return Qnil; }
+
+      /* call-seq: baz -> nil */
+      VALUE foo_baz(VALUE self) { return Qnil; }
+
+      void Init_Foo(void) {
+        cFoo = rb_define_class("Foo", rb_cObject);
+        rb_define_method(cFoo, "bar", foo_bar, 0);
+        rb_define_method(cFoo, "baz", foo_baz, 0);
+      }
+    C
+
+    util_get_class updated_content, 'cFoo'
+
+    klass = @store.find_class_named 'Foo'
+    method_names = klass.method_list.map(&:name)
+    assert_equal 2, method_names.size
+    assert_include method_names, 'bar'
+    assert_include method_names, 'baz'
+  end
+
   def util_get_class(content, name = nil)
     @parser = util_parser content
     @parser.scan