backport fix for #4565 don't duplicate block attribute line above det…

…ached block that breaks a dlist

CHANGELOG.adoc

@@ -21,6 +21,7 @@ This project utilizes semantic versioning.
 Bug Fixes::
 
   * Don't leave behind empty line inside skipped preprocessor conditional (#4580)
+  * Don't duplicate block attribute line above detached block that breaks a dlist; fixes duplicate role on detached block (#4565)
 
 == 2.0.22 (2024-03-08) - @mojavelinux
 

lib/asciidoctor/parser.rb

@@ -1476,6 +1476,7 @@ def self.read_lines_for_list_item(reader, list_type, sibling_trait = nil, has_te
           break
         end
         if interrupt
+          this_line = nil
           reader.unshift_lines block_attribute_lines
           break
         end

test/lists_test.rb

@@ -4204,7 +4204,23 @@ def 1
       assert_xpath '//*[@class="dlist"]/following-sibling::*[@class="exampleblock"]//p[text()="detached"]', output, 1
     end
 
-    test 'attribute line breaks list even when term has no inline description' do
+    test 'block attribute line above delimited block that breaks a dlist is not duplicated' do
+      input = <<~'EOS'
+      == Lists
+
+      term:: desc
+      [.rolename]
+      ----
+      detached
+      ----
+      EOS
+
+      output = convert_string_to_embedded input
+      assert_xpath '//*[@class="dlist"]/dl', output, 1
+      assert_xpath '//*[@class="dlist"]/following-sibling::*[@class="listingblock rolename"]', output, 1
+    end
+
+    test 'block attribute line above paragraph breaks list even when term has no inline description' do
       input = <<~'EOS'
       == Lists
 
@@ -4220,7 +4236,21 @@ def 1
       assert_xpath '//*[@class="dlist"]/following-sibling::*[@class="verseblock"]/pre[text()="detached"]', output, 1
     end
 
-    test 'id line breaks list even when term has no inline description' do
+    test 'block attribute line above paragraph that breaks a dlist is not duplicated' do
+      input = <<~'EOS'
+      == Lists
+
+      term:: desc
+      [.rolename]
+      detached
+      EOS
+
+      output = convert_string_to_embedded input
+      assert_xpath '//*[@class="dlist"]/dl', output, 1
+      assert_xpath '//*[@class="dlist"]/following-sibling::*[@class="paragraph rolename"]', output, 1
+    end
+
+    test 'block anchor line breaks list even when term has no inline description' do
       input = <<~'EOS'
       == Lists