resolves #4151 don't promote level-0 special section at start of document to document title (PR #4152)

3 files changed, 42 insertions, 4 deletions

diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index e6b47b4b..6ddad584 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -24,6 +24,10 @@ Enhancements::
   * Add `--sourcemap` option to the CLI to enable the `:sourcemap` option on the parser (#3569) *@hackingotter*
   * Allow section ID to be unset by assigning an empty value to the `id` block attribute (#4139)
 
+Compliance::
+
+  * Don't promote level-0 special section at start of document to document title (#4151)
+
 Bug Fixes::
 
   * Remove unnamespaced selectors in Pygments stylesheet
diff --git a/lib/asciidoctor/parser.rb b/lib/asciidoctor/parser.rb
index f54d07f6..628b79dc 100644
--- a/lib/asciidoctor/parser.rb
+++ b/lib/asciidoctor/parser.rb
@@ -123,9 +123,9 @@ class Parser
     block_attrs = reader.skip_blank_lines ? (parse_block_metadata_lines reader, document) : {}
     doc_attrs = document.attributes
 
-    # special case, block title is not allowed above document title,
+    # special cases, block style or title is not allowed above document title,
     # carry attributes over to the document body
-    if (implicit_doctitle = is_next_line_doctitle? reader, block_attrs, doc_attrs['leveloffset']) && block_attrs['title']
+    if (implicit_doctitle = is_next_line_doctitle? reader, block_attrs, doc_attrs['leveloffset']) && (block_attrs['title'] || block_attrs['style'])
       return document.finalize_header block_attrs, false
     end
 
diff --git a/test/sections_test.rb b/test/sections_test.rb
index 84ecd485..c28e53b1 100644
--- a/test/sections_test.rb
+++ b/test/sections_test.rb
@@ -616,9 +616,25 @@ context 'Sections' do
         assert_xpath '//a[text()="Reference Manual"]', output, 1
       end
 
-      test 'should discard style, role and options shorthand attributes defined on document title' do
+      test 'should not interpret level-0 section as document title if it has a style' do
         input = <<~'EOS'
-        [style#idname.rolename%optionname]
+        [glossary]
+        = Document Title
+
+        content
+        EOS
+        using_memory_logger do |logger|
+          doc = document_from_string input
+          assert_message logger, :ERROR, '<stdin>: line 2: level 0 sections can only be used when doctype is book', Hash
+          refute doc.header?
+          assert_nil doc.attributes['title']
+          assert_equal 'glossary', doc.blocks[0].attributes['style']
+        end
+      end
+
+      test 'should discard role and options shorthand attributes defined on document title' do
+        input = <<~'EOS'
+        [#idname.rolename%optionname]
         = Document Title
 
         content
@@ -2111,6 +2127,24 @@ context 'Sections' do
       assert appendix.numbered
     end
 
+    test 'should not promote level-0 special section in book doctype to document title' do
+      input = <<~'EOS'
+      :doctype: book
+
+      [appendix]
+      = Installation
+
+      Installation details here.
+      EOS
+
+      doc = document_from_string input
+      refute doc.header?
+      assert_nil doc.attributes['title']
+      appendix = doc.blocks[0]
+      assert_equal 'appendix', appendix.sectname
+      assert_equal 'Appendix A: ', appendix.caption
+    end
+
     test 'should prefix appendix title by numbered label even when section numbering is disabled' do
       input = <<~'EOS'
       [appendix]