From 8c921500e2c890fe2e9135a31a3293672c297faa Mon Sep 17 00:00:00 2001
From: Explorer09 <explorer09@gmail.com>
Date: Mon, 12 Aug 2024 20:01:44 +0800
Subject: [PATCH] Add a placeholder text for print_backtrace()...

in case backtrace(3) returns a zero or negative "nptrs" value.
---
 CRT.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/CRT.c b/CRT.c
index a60857a17..9c8b841a2 100644
--- a/CRT.c
+++ b/CRT.c
@@ -1261,7 +1261,13 @@ static void print_backtrace(void) {
    void* backtraceArray[256];
 
    int nptrs = backtrace(backtraceArray, ARRAYSIZE(backtraceArray));
-   backtrace_symbols_fd(backtraceArray, nptrs, STDERR_FILENO);
+   if (nptrs > 0) {
+      backtrace_symbols_fd(backtraceArray, nptrs, STDERR_FILENO);
+   } else {
+      full_write_str(STDERR_FILENO,
+         "[No backtrace information available from libc]\n"
+      );
+   }
 #else
 #error No implementation for print_backtrace()!
 #endif