From 8e596c60505c21768064afaeee6ff7814668b44a Mon Sep 17 00:00:00 2001
From: Jeff Epler <jepler@gmail.com>
Date: Wed, 20 Aug 2025 16:16:15 -0500
Subject: [PATCH] unix: Don't crash if heap locked in prompt_write_history.

Signed-off-by: Jeff Epler <jepler@gmail.com>
---
 ports/unix/input.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/ports/unix/input.c b/ports/unix/input.c
index 31926a5a8e..260e9eac8c 100644
--- a/ports/unix/input.c
+++ b/ports/unix/input.c
@@ -104,6 +104,9 @@ void prompt_write_history(void) {
     #if MICROPY_USE_READLINE == 1
     char *home = getenv("HOME");
     if (home != NULL) {
+        if (MP_STATE_THREAD(gc_lock_depth) != 0) {
+            return;
+        }
         vstr_t vstr;
         vstr_init(&vstr, 50);
         vstr_printf(&vstr, "%s/.micropython.history", home);