From f1c552ea32062dd70861ad0292d54e2888c7d891 Mon Sep 17 00:00:00 2001
From: yuxi-liu-wired <33951560+yuxi-liu-wired@users.noreply.github.com>
Date: Sun, 4 Oct 2026 21:36:56 +0000
Subject: [PATCH] Keep the last closer position in the backtick cache

scan_to_closing_backticks records, for each backtick-string length, the
position of the last such string it saw, so a later opener can tell
there is no closer without rescanning. A scan that starts after an
earlier one had already reached the end of the input overwrote a later
position with an earlier one. A following opener of that length then
saw a closer position before itself and gave up:

    ``x
    `i`
    `j`

rendered `` `j` `` as text instead of a code span. Store a position only
if it is past the one already recorded.
---
 src/inlines.c       |  6 ++++--
 test/regression.txt | 13 +++++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/inlines.c b/src/inlines.c
index bf765eab5..abaeb96e1 100644
--- a/src/inlines.c
+++ b/src/inlines.c
@@ -342,8 +342,10 @@ static bufsize_t scan_to_closing_backticks(subject *subj,
       advance(subj);
       numticks++;
     }
-    // store position of ender
-    if (numticks <= MAXBACKTICKS) {
+    // store position of ender (keep the last one: a scan that resumes after
+    // an earlier full scan must not replace a later position)
+    if (numticks <= MAXBACKTICKS &&
+        subj->backticks[numticks] < subj->pos - numticks) {
       subj->backticks[numticks] = subj->pos - numticks;
     }
     if (numticks == openticklength) {
diff --git a/test/regression.txt b/test/regression.txt
index 1426617ab..6456ccbf8 100644
--- a/test/regression.txt
+++ b/test/regression.txt
@@ -257,6 +257,19 @@ x <- 1
 </code></pre>
 ````````````````````````````````
 
+Code spans after an unmatched backtick string of a different length.
+The failed scan for the closer of ``` `` ``` must not hide the second
+single-backtick span.
+```````````````````````````````` example
+``x
+`i`
+`j`
+.
+<p>``x
+<code>i</code>
+<code>j</code></p>
+````````````````````````````````
+
 https://github.com/commonmark/commonmark.js/issues/283
 ```````````````````````````````` example
 x<!x>