From 962ccf0ab5036480fe7aca69f83dfbe35e72be1f Mon Sep 17 00:00:00 2001
From: Gerhard Schlager <gerhard.schlager@discourse.org>
Date: Fri, 17 Sep 2021 10:41:34 +0200
Subject: [PATCH] FIX: Hoisting linebreaks shouldn't fail for HTML5 elements
 (#14364)

---
 lib/html_to_markdown.rb                  | 11 ++++++++---
 spec/components/html_to_markdown_spec.rb | 10 ++++++----
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/lib/html_to_markdown.rb b/lib/html_to_markdown.rb
index d602c2d1174..6cd05ded831 100644
--- a/lib/html_to_markdown.rb
+++ b/lib/html_to_markdown.rb
@@ -53,7 +53,7 @@ class HtmlToMarkdown
       doc.css("br.#{klass}").each do |br|
         parent = br.parent
 
-        if parent.description.block?
+        if block?(parent)
           br.remove_class(klass)
         else
           before, after = parent.children.slice_when { |n| n == br }.to_a
@@ -194,7 +194,7 @@ class HtmlToMarkdown
   BLOCKS ||= %w{div tr}
   BLOCKS.each do |tag|
     define_method("visit_#{tag}") do |node|
-      prefix = node.previous_element&.description&.block? ? "" : "\n"
+      prefix = block?(node.previous_element) ? "" : "\n"
       "#{prefix}#{traverse(node)}\n"
     end
   end
@@ -283,7 +283,7 @@ class HtmlToMarkdown
   LISTS ||= %w{ul ol}
   LISTS.each do |tag|
     define_method("visit_#{tag}") do |node|
-      prefix = node.previous_element&.description&.block? ? "" : "\n"
+      prefix = block?(node.previous_element) ? "" : "\n"
       suffix = node.ancestors("ul, ol, li").size > 0 ? "" : "\n"
       "#{prefix}#{traverse(node)}#{suffix}"
     end
@@ -358,4 +358,9 @@ class HtmlToMarkdown
     node.text
   end
 
+  HTML5_BLOCK_ELEMENTS ||= %w[article aside details dialog figcaption figure footer header main nav section]
+  def block?(node)
+    return false if !node
+    node.description&.block? || HTML5_BLOCK_ELEMENTS.include?(node.name)
+  end
 end
diff --git a/spec/components/html_to_markdown_spec.rb b/spec/components/html_to_markdown_spec.rb
index ea24eb8e66a..f95da5c8abb 100644
--- a/spec/components/html_to_markdown_spec.rb
+++ b/spec/components/html_to_markdown_spec.rb
@@ -38,9 +38,9 @@ describe HtmlToMarkdown do
     HTML
 
     markdown = <<~MD
-       Let me see if it happens by answering your message through Thunderbird.
+      Let me see if it happens by answering your message through Thunderbird.
 
-       Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1
+      Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1 Long sentence 1
     MD
 
     expect(html_to_markdown(html)).to eq(markdown.strip)
@@ -70,13 +70,15 @@ describe HtmlToMarkdown do
     html = <<~HTML
       <aside class="quote no-group">
       <blockquote>
-      <p>hello.</p>
+      <p>Hello,<br>is it me you're looking for?</p>
       </blockquote>
+      <br>
       </aside>
     HTML
 
     markdown = <<~MD
-      > hello.
+      > Hello,
+      > is it me you're looking for?
     MD
 
     expect(html_to_markdown(html)).to eq(markdown.strip)