Fix lint issues and legacy anchor casing bug

- Change legacy anchor elements from <a> to <span> to fix lint errors
  (accessibility: <a> elements require href attribute)
- Fix legacy anchor casing: use legacy_aref for context prefix to preserve
  original casing (e.g., module-RDoc instead of module-rdoc)
- Add regression tests for legacy anchor casing

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: st0012

lib/rdoc/generator/template/aliki/class.rhtml

@@ -29,7 +29,7 @@
     </ol>
   <% end %>
 
-  <a id="<%= h klass.legacy_aref %>" class="legacy-anchor"></a>
+  <span id="<%= h klass.legacy_aref %>" class="legacy-anchor"></span>
   <h1 id="<%= h klass.aref %>" class="anchor-link <%= klass.type %>">
     <%= klass.type %> <%= klass.full_name %>
   </h1>
@@ -39,7 +39,7 @@
   </section>
 
   <%- klass.each_section do |section, constants, attributes| %>
-  <a id="<%= section.legacy_aref %>" class="legacy-anchor"></a>
+  <span id="<%= section.legacy_aref %>" class="legacy-anchor"></span>
   <section id="<%= section.aref %>" class="documentation-section anchor-link">
     <%- if section.title then %>
     <header class="documentation-section-title">

lib/rdoc/generator/template/darkfish/class.rhtml

@@ -33,7 +33,7 @@
     </ol>
   <% end %>
 
-  <a id="<%= h klass.legacy_aref %>" class="legacy-anchor"></a>
+  <span id="<%= h klass.legacy_aref %>" class="legacy-anchor"></span>
   <h1 id="<%= h klass.aref %>" class="anchor-link <%= klass.type %>">
     <%= klass.type %> <%= klass.full_name %>
   </h1>
@@ -43,7 +43,7 @@
   </section>
 
   <%- klass.each_section do |section, constants, attributes| %>
-  <a id="<%= section.legacy_aref %>" class="legacy-anchor"></a>
+  <span id="<%= section.legacy_aref %>" class="legacy-anchor"></span>
   <section id="<%= section.aref %>" class="documentation-section anchor-link">
     <%- if section.title then %>
     <header class="documentation-section-title">

lib/rdoc/markup/heading.rb

@@ -125,13 +125,17 @@ def label(context = nil)
       #   "Hello World" -> "label-Hello+World"
       #
       # Examples (with context being class Foo):
-      #   "hello"       -> "class-foo-label-hello"
-      #   "Hello World" -> "class-foo-label-Hello+World"
+      #   "hello"       -> "class-Foo-label-hello"
+      #   "Hello World" -> "class-Foo-label-Hello+World"
       #
       #: (RDoc::Context?) -> String
       def legacy_label(context = nil)
         result = +""
-        result << "#{context.aref}-" if context&.respond_to?(:aref)
+        if context&.respond_to?(:legacy_aref)
+          result << "#{context.legacy_aref}-"
+        elsif context&.respond_to?(:aref)
+          result << "#{context.aref}-"
+        end
         result << legacy_aref
         result
       end

lib/rdoc/markup/to_html.rb

@@ -317,7 +317,7 @@ def accept_heading(heading)
     # Add legacy anchor before the heading for backward compatibility.
     # This allows old links with label- prefix to still work.
     if legacy_label && @options.output_decoration && !@options.pipe
-      @res << "\n<a id=\"#{legacy_label}\" class=\"legacy-anchor\"></a>"
+      @res << "\n<span id=\"#{legacy_label}\" class=\"legacy-anchor\"></span>"
     end
 
     @res << if @options.output_decoration

test/rdoc/generator/darkfish_test.rb

@@ -126,7 +126,8 @@ def test_generate
     )
 
     # GitHub-style: heading-1 (lowercase, dot removed)
-    assert_match(/<a id="class-klass-label-Heading\+1" class="legacy-anchor"><\/a>\s*<h1 id="class-klass-heading-1"><a href="#class-klass-heading-1">Heading 1<\/a>(?!\.)/,
+    # Legacy anchor preserves original casing (class-Klass), while new anchor is lowercase (class-klass)
+    assert_match(/<span id="class-Klass-label-Heading\+1" class="legacy-anchor"><\/span>\s*<h1 id="class-klass-heading-1"><a href="#class-klass-heading-1">Heading 1<\/a>(?!\.)/,
                  klass[%r[<section class=\"description\">.*</section>]m])
     toc = File.binread('table_of_contents.html')
     assert_match(
@@ -173,7 +174,7 @@ def test_generate_index_with_main_page
 
     assert_include index_html, "<h3>Table of Contents</h3>"
     # GitHub-style: heading-1 (lowercase, space to hyphen)
-    assert_include index_html, '<a id="label-Heading+1" class="legacy-anchor"></a>
+    assert_include index_html, '<span id="label-Heading+1" class="legacy-anchor"></span>
 <h1 id="heading-1"><a href="#heading-1">Heading 1</a>'
     # When there's a main page, the default description should not be shown
     assert_not_include index_html, 'This is the API documentation for My awesome Ruby project.'

test/rdoc/generator/markup_test.rb

@@ -39,7 +39,7 @@ def test_description
     @comment = '= Hello'
 
     # When there's no context (self returns nil for aref), there's no context prefix in the legacy label
-    assert_equal "\n<a id=\"label-Hello\" class=\"legacy-anchor\"></a>\n<h1 id=\"hello\"><a href=\"#hello\">Hello</a></h1>\n", description
+    assert_equal "\n<span id=\"label-Hello\" class=\"legacy-anchor\"></span>\n<h1 id=\"hello\"><a href=\"#hello\">Hello</a></h1>\n", description
   end
 
   def test_formatter

test/rdoc/markup/heading_test.rb

@@ -24,6 +24,36 @@ def test_label
     assert_equal 'class-foo-hello-friend', @h.label(context)
   end
 
+  def test_legacy_aref
+    # Legacy style: label- prefix, original casing, + for spaces
+    # Note: *Friend* markup is stripped, ! becomes %21 which becomes -21
+    assert_equal 'label-Hello+Friend-21', @h.legacy_aref
+  end
+
+  def test_legacy_label
+    # Legacy style without context
+    assert_equal 'label-Hello+Friend-21', @h.legacy_label
+    assert_equal 'label-Hello+Friend-21', @h.legacy_label(nil)
+
+    # Legacy style with context - context should preserve original casing (class-Foo, not class-foo)
+    context = RDoc::NormalClass.new 'Foo'
+    assert_equal 'class-Foo-label-Hello+Friend-21', @h.legacy_label(context)
+  end
+
+  def test_legacy_label_preserves_context_casing
+    # Verify that legacy_label uses legacy_aref for the context prefix (preserving original casing)
+    # This is a regression test for a bug where legacy_label incorrectly lowercased the context prefix
+    h = RDoc::Markup::Heading.new 1, 'Credits'
+    context = RDoc::NormalModule.new 'RDoc'
+    assert_equal 'module-RDoc-label-Credits', h.legacy_label(context)
+
+    # Nested module example
+    parent = RDoc::NormalModule.new 'Foo'
+    context = RDoc::NormalClass.new 'Bar'
+    context.parent = parent
+    assert_equal 'class-Foo::Bar-label-Credits', h.legacy_label(context)
+  end
+
   def test_plain_html
     assert_equal 'Hello <strong>Friend</strong>!', @h.plain_html
   end

test/rdoc/markup/to_html_test.rb

@@ -24,34 +24,34 @@ def accept_document
   end
 
   def accept_heading
-    assert_equal "\n<a id=\"label-Hello\" class=\"legacy-anchor\"></a>\n<h5 id=\"hello\"><a href=\"#hello\">Hello</a></h5>\n", @to.res.join
+    assert_equal "\n<span id=\"label-Hello\" class=\"legacy-anchor\"></span>\n<h5 id=\"hello\"><a href=\"#hello\">Hello</a></h5>\n", @to.res.join
   end
 
   def accept_heading_1
-    assert_equal "\n<a id=\"label-Hello\" class=\"legacy-anchor\"></a>\n<h1 id=\"hello\"><a href=\"#hello\">Hello</a></h1>\n", @to.res.join
+    assert_equal "\n<span id=\"label-Hello\" class=\"legacy-anchor\"></span>\n<h1 id=\"hello\"><a href=\"#hello\">Hello</a></h1>\n", @to.res.join
   end
 
   def accept_heading_2
-    assert_equal "\n<a id=\"label-Hello\" class=\"legacy-anchor\"></a>\n<h2 id=\"hello\"><a href=\"#hello\">Hello</a></h2>\n", @to.res.join
+    assert_equal "\n<span id=\"label-Hello\" class=\"legacy-anchor\"></span>\n<h2 id=\"hello\"><a href=\"#hello\">Hello</a></h2>\n", @to.res.join
   end
 
   def accept_heading_3
-    assert_equal "\n<a id=\"label-Hello\" class=\"legacy-anchor\"></a>\n<h3 id=\"hello\"><a href=\"#hello\">Hello</a></h3>\n", @to.res.join
+    assert_equal "\n<span id=\"label-Hello\" class=\"legacy-anchor\"></span>\n<h3 id=\"hello\"><a href=\"#hello\">Hello</a></h3>\n", @to.res.join
   end
 
   def accept_heading_4
-    assert_equal "\n<a id=\"label-Hello\" class=\"legacy-anchor\"></a>\n<h4 id=\"hello\"><a href=\"#hello\">Hello</a></h4>\n", @to.res.join
+    assert_equal "\n<span id=\"label-Hello\" class=\"legacy-anchor\"></span>\n<h4 id=\"hello\"><a href=\"#hello\">Hello</a></h4>\n", @to.res.join
   end
 
   def accept_heading_b
     inner = "<strong>Hello</strong>"
 
-    assert_equal "\n<a id=\"label-Hello\" class=\"legacy-anchor\"></a>\n<h1 id=\"hello\"><a href=\"#hello\">#{inner}</a></h1>\n",
+    assert_equal "\n<span id=\"label-Hello\" class=\"legacy-anchor\"></span>\n<h1 id=\"hello\"><a href=\"#hello\">#{inner}</a></h1>\n",
                  @to.res.join
   end
 
   def accept_heading_suppressed_crossref
-    assert_equal "\n<a id=\"label-Hello\" class=\"legacy-anchor\"></a>\n<h1 id=\"hello\"><a href=\"#hello\">Hello</a></h1>\n", @to.res.join
+    assert_equal "\n<span id=\"label-Hello\" class=\"legacy-anchor\"></span>\n<h1 id=\"hello\"><a href=\"#hello\">Hello</a></h1>\n", @to.res.join
   end
 
   def accept_list_end_bullet
@@ -327,7 +327,7 @@ def test_accept_heading_7
 
     @to.accept_heading @RM::Heading.new(7, 'Hello')
 
-    assert_equal "\n<a id=\"label-Hello\" class=\"legacy-anchor\"></a>\n<h6 id=\"hello\"><a href=\"#hello\">Hello</a></h6>\n", @to.res.join
+    assert_equal "\n<span id=\"label-Hello\" class=\"legacy-anchor\"></span>\n<h6 id=\"hello\"><a href=\"#hello\">Hello</a></h6>\n", @to.res.join
   end
 
   def test_accept_heading_aref_class
@@ -336,7 +336,7 @@ def test_accept_heading_aref_class
 
     @to.accept_heading head(1, 'Hello')
 
-    assert_equal "\n<a id=\"class-foo-label-Hello\" class=\"legacy-anchor\"></a>\n<h1 id=\"class-foo-hello\"><a href=\"#class-foo-hello\">Hello</a></h1>\n",
+    assert_equal "\n<span id=\"class-Foo-label-Hello\" class=\"legacy-anchor\"></span>\n<h1 id=\"class-foo-hello\"><a href=\"#class-foo-hello\">Hello</a></h1>\n",
                  @to.res.join
   end
 
@@ -346,7 +346,7 @@ def test_accept_heading_aref_method
 
     @to.accept_heading @RM::Heading.new(1, 'Hello')
 
-    assert_equal "\n<a id=\"method-i-foo-label-Hello\" class=\"legacy-anchor\"></a>\n<h1 id=\"method-i-foo-hello\"><a href=\"#method-i-foo-hello\">Hello</a></h1>\n",
+    assert_equal "\n<span id=\"method-i-foo-label-Hello\" class=\"legacy-anchor\"></span>\n<h1 id=\"method-i-foo-hello\"><a href=\"#method-i-foo-hello\">Hello</a></h1>\n",
                  @to.res.join
   end