From edd9d73b0da03f9220493be6ad3d590f3bab0d5f Mon Sep 17 00:00:00 2001
From: Robert Burke <robert.burke@ltcm.lol>
Date: Wed, 11 Jan 2023 20:37:25 +0000
Subject: [PATCH] Fix buffer overflow in fmt when DAZ is set

---
 lib/std/fmt/errol.zig | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/std/fmt/errol.zig b/lib/std/fmt/errol.zig
index 1ce72de0fc..1c67175ede 100644
--- a/lib/std/fmt/errol.zig
+++ b/lib/std/fmt/errol.zig
@@ -169,7 +169,8 @@ fn errolSlow(val: f64, buffer: []u8) FloatDecimal {
 
     // digit generation
     var buf_index: usize = 0;
-    while (true) {
+    const bound = buffer.len - 1;
+    while (buf_index < bound) {
         var hdig = @floatToInt(u8, @floor(high.val));
         if ((high.val == @intToFloat(f64, hdig)) and (high.off < 0)) hdig -= 1;