From d97a3ce3604b838b3a04ae5ebf3c962f8a18a2b4 Mon Sep 17 00:00:00 2001
From: DualFroz <me@dualfroz.com>
Date: Wed, 7 Oct 2026 20:14:16 +0200
Subject: [PATCH] fix: allow a tab or end of input after a type 6 html block
 tag name

the type 6 html block start only accepted spaces, a newline, > or /> after the tag name. commonmark 0.31.2 also allows a tab and the end of the line, which includes the end of the input.
---
 src/rules.ts                                     |  2 +-
 .../specs/new/html_block_tab_after_tag_name.html | 15 +++++++++++++++
 test/specs/new/html_block_tab_after_tag_name.md  | 16 ++++++++++++++++
 .../new/html_block_tag_at_end_of_input.html      |  2 ++
 test/specs/new/html_block_tag_at_end_of_input.md |  3 +++
 5 files changed, 37 insertions(+), 1 deletion(-)
 create mode 100644 test/specs/new/html_block_tab_after_tag_name.html
 create mode 100644 test/specs/new/html_block_tab_after_tag_name.md
 create mode 100644 test/specs/new/html_block_tag_at_end_of_input.html
 create mode 100644 test/specs/new/html_block_tag_at_end_of_input.md

diff --git a/src/rules.ts b/src/rules.ts
index 81da76a..2ae1b68 100644
--- a/src/rules.ts
+++ b/src/rules.ts
@@ -162,7 +162,7 @@ const html = edit(
 + '|<\\?[\\s\\S]*?(?:\\?>[^\\n]*\\n*|$)' // (3)
 + '|<![A-Z][\\s\\S]*?(?:>[^\\n]*\\n*|$)' // (4)
 + '|<!\\[CDATA\\[[\\s\\S]*?(?:\\]\\]>[^\\n]*\\n*|$)' // (5)
-+ '|</?(tag)(?: +|\\n|/?>)[\\s\\S]*?(?:(?:\\n[ \t]*)+\\n|$)' // (6)
++ '|</?(tag)(?:[ \\t]+|\\n|/?>|$)[\\s\\S]*?(?:(?:\\n[ \t]*)+\\n|$)' // (6)
 + '|<(?!(?:script|pre|style|textarea)(?![a-z0-9-]))([a-z][a-z0-9-]*)(?:attribute)*? */?>(?=[ \\t]*(?:\\n|$))[\\s\\S]*?(?:(?:\\n[ \t]*)+\\n|$)' // (7) open tag
 + '|</[a-z][a-z0-9-]*\\s*>(?=[ \\t]*(?:\\n|$))[\\s\\S]*?(?:(?:\\n[ \t]*)+\\n|$)' // (7) closing tag
 + ')', 'i')
diff --git a/test/specs/new/html_block_tab_after_tag_name.html b/test/specs/new/html_block_tab_after_tag_name.html
new file mode 100644
index 0000000..536dd7f
--- /dev/null
+++ b/test/specs/new/html_block_tab_after_tag_name.html
@@ -0,0 +1,15 @@
+<div	class="x">
+*stays raw*
+</div>
+<TABLE	class="x"><tr><td>
+*stays raw*
+</td></tr></TABLE>
+<div	
+class="x">
+*stays raw*
+</div>
+<blockquote>
+<div	class="x">
+*stays raw*
+</div>
+</blockquote>
diff --git a/test/specs/new/html_block_tab_after_tag_name.md b/test/specs/new/html_block_tab_after_tag_name.md
new file mode 100644
index 0000000..85d6aae
--- /dev/null
+++ b/test/specs/new/html_block_tab_after_tag_name.md
@@ -0,0 +1,16 @@
+<div	class="x">
+*stays raw*
+</div>
+
+<TABLE	class="x"><tr><td>
+*stays raw*
+</td></tr></TABLE>
+
+<div	
+class="x">
+*stays raw*
+</div>
+
+> <div	class="x">
+> *stays raw*
+> </div>
diff --git a/test/specs/new/html_block_tag_at_end_of_input.html b/test/specs/new/html_block_tag_at_end_of_input.html
new file mode 100644
index 0000000..3f54666
--- /dev/null
+++ b/test/specs/new/html_block_tag_at_end_of_input.html
@@ -0,0 +1,2 @@
+<p>Paragraph</p>
+<div
diff --git a/test/specs/new/html_block_tag_at_end_of_input.md b/test/specs/new/html_block_tag_at_end_of_input.md
new file mode 100644
index 0000000..c5a9688
--- /dev/null
+++ b/test/specs/new/html_block_tag_at_end_of_input.md
@@ -0,0 +1,3 @@
+Paragraph
+
+<div
\ No newline at end of file