From 21999b9f3523bce2459ef9ac1bc4ac5805994bc3 Mon Sep 17 00:00:00 2001
From: BathreeNode <101283333+batuhankocyigit@users.noreply.github.com>
Date: Wed, 12 Aug 2026 11:34:15 +0300
Subject: [PATCH] Add files via upload

---
 scripts/md-exec.md | 11 +++++++++++
 scripts/md-exec.py |  9 +++++++--
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/scripts/md-exec.md b/scripts/md-exec.md
index b1c75f03..13ecf984 100644
--- a/scripts/md-exec.md
+++ b/scripts/md-exec.md
@@ -219,6 +219,17 @@ blah
 EOF
 ```
 
+A heredoc body may itself contain a line starting with ` ``` ` (e.g. a
+heredoc that writes out markdown) without being mistaken for the end of
+the code block:
+```sh {empty_output}
+$ cat > /tmp/md-exec-fence.txt << 'EOF'
+before
+```
+after
+EOF
+```
+
 ---
 
 ## Global Directives
diff --git a/scripts/md-exec.py b/scripts/md-exec.py
index 749c1449..de78588a 100644
--- a/scripts/md-exec.py
+++ b/scripts/md-exec.py
@@ -189,8 +189,13 @@ def parse(self):
 
             stripped = line.strip()
 
-            # Detect Code Snippets
-            if stripped.startswith("```"):
+            # Detect Code Snippets. Skip fence detection while inside an
+            # open heredoc body -- the heredoc content may legitimately
+            # contain a line starting with ``` (e.g. a heredoc that writes
+            # out markdown), and treating it as a fence boundary would cut
+            # the code block short mid-heredoc, leaving the shell command
+            # truncated and the heredoc unterminated.
+            if stripped.startswith("```") and heredoc_delimiter is None:
                 if in_block:
                     # End of block: save pending test
                     if current_cmd: