From d9969c57343d48a4d1fac12f3f5c4b2fd82d8da5 Mon Sep 17 00:00:00 2001
From: fisker Cheung <lionkay@gmail.com>
Date: Sun, 23 Aug 2026 16:13:56 +0800
Subject: [PATCH] Fix `isSetextHeading` (#19912)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
---
 src/language-markdown/utilities.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/language-markdown/utilities.js b/src/language-markdown/utilities.js
index a11db88cf..9c4605d95 100644
--- a/src/language-markdown/utilities.js
+++ b/src/language-markdown/utilities.js
@@ -317,8 +317,9 @@ function hasPrettierIgnore(path) {
 }
 
 function isSetextHeading(node) {
-  const { start, end } = node.position;
-  return start.line !== end.line;
+  return (
+    node.type === "heading" && node.position.start.line < node.position.end.line
+  );
 }
 
 const isNewLine = (node) => node?.type === "whitespace" && node.value === "\n";