From b43575545272aeecf4e140b47485f94131430123 Mon Sep 17 00:00:00 2001
From: Frederick Zhang <frederick888@tsundere.moe>
Date: Fri, 7 Jan 2022 05:51:47 +1100
Subject: [PATCH] fix(runtime): check markdownError before syn-clear (#16930)

Avoids `E28: No such highlight group name: markdownError` when using a
foreign markdown syntax.
---
 runtime/syntax/checkhealth.vim | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/runtime/syntax/checkhealth.vim b/runtime/syntax/checkhealth.vim
index dff880a0bc..37f1822740 100644
--- a/runtime/syntax/checkhealth.vim
+++ b/runtime/syntax/checkhealth.vim
@@ -12,7 +12,9 @@ unlet! b:current_syntax
 syn case match
 
 " We do not care about markdown syntax errors
-syn clear markdownError
+if hlexists('markdownError')
+  syn clear markdownError
+endif
 
 syn keyword healthError ERROR[:] containedin=markdownCodeBlock,mkdListItemLine
 syn keyword healthWarning WARNING[:] containedin=markdownCodeBlock,mkdListItemLine