From 42262a7c53cef75f17de52b76cfdbdd5daf5b4f7 Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Tue, 29 Oct 2024 22:52:56 +0100
Subject: [PATCH] Don't segfault on missing line number data (#641)

Can be reproduced on the CLI but not from a script:

    # should throw "unsupported object class" TypeError
    $ qjs --std -e 'bjson.write(function(){})'
    /path/to/quickjs.c:6510:15: runtime error: applying zero offset to null pointer
---
 quickjs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/quickjs.c b/quickjs.c
index 62cf799..40f1842 100644
--- a/quickjs.c
+++ b/quickjs.c
@@ -6507,6 +6507,8 @@ static int find_line_num(JSContext *ctx, JSFunctionBytecode *b,
 
     *col = 1;
     p = b->pc2line_buf;
+    if (!p)
+        goto fail;
     p_end = p + b->pc2line_len;
     pc = 0;
     line_num = b->line_num;