Fix section comments with the prism parser

lib/rdoc/code_object/context/section.rb

@@ -106,6 +106,9 @@ def legacy_aref
   #
   #   # :section: The title
   #   # The body
+  #
+  #--
+  # TODO Remove when the ripper parser has been removed
 
   def extract_comment(comment)
     case comment

lib/rdoc/parser/prism_ruby.rb

@@ -473,15 +473,28 @@ def parse_comment_text_to_directives(comment_text, start_line) # :nodoc:
     comment.line = start_line
     markup, = directives['markup']
     comment.format = markup&.downcase || @markup
-    if (section, = directives['section'])
+    if (section, directive_line = directives['section'])
       # If comment has :section:, it is not a documentable comment for a code object
-      @container.set_current_section(section, comment.dup)
+      comment.text = extract_section_comment(comment_text, directive_line - start_line)
+      @container.set_current_section(section, comment)
       return
     end
     @preprocess.run_post_processes(comment, @container)
     [comment, directives]
   end
 
+  # Extracts the comment for this section from the normalized comment block.
+  # Removes all lines before the line that contains :section:
+  # If the comment also ends with the same content, remove it as well
+
+  def extract_section_comment(comment_text, prefix_line_count) # :nodoc:
+    prefix = comment_text.lines[0...prefix_line_count].join
+    comment_text.delete_prefix!(prefix)
+    # Comment is already normalized and doesn't end with a newline
+    comment_text.delete_suffix!(prefix.chomp)
+    comment_text
+  end
+
   def slice_tokens(start_pos, end_pos) # :nodoc:
     start_index = @tokens.bsearch_index { |t| ([t.line_no, t.char_no] <=> start_pos) >= 0 }
     end_index = @tokens.bsearch_index { |t| ([t.line_no, t.char_no] <=> end_pos) >= 0 }

test/rdoc/parser/prism_ruby_test.rb

@@ -36,6 +36,41 @@ def test_look_for_directives_in_section
     assert_equal 'new section', section.title
   end
 
+  def test_section_with_divider
+    util_parser <<~RUBY
+      # DIVIDER
+      # :section: section 1
+      # foo
+      # DIVIDER
+
+      # DIVIDER 1
+      # DIVIDER 2
+      # :section: section 2
+      # foo
+      # DIVIDER 1
+      # DIVIDER 2
+
+      # DIVIDER TOP ONLY
+      # :section: section 3
+      # foo
+
+      # DIVIDER TOP ONLY
+      # :section: section 4
+    RUBY
+
+    section = @top_level.sections_hash['section 1']
+    assert_equal "\n<p>foo</p>\n", section.description
+
+    section = @top_level.sections_hash['section 2']
+    assert_equal "\n<p>foo</p>\n", section.description
+
+    section = @top_level.sections_hash['section 3']
+    assert_equal "\n<p>foo</p>\n", section.description
+
+    section = @top_level.sections_hash['section 4']
+    assert_equal '', section.description
+  end
+
   def test_look_for_directives_in_commented
     util_parser <<~RUBY
       # how to make a section: