From 680867cdb5ff5334e8d10a46d250e9e01da2db4c Mon Sep 17 00:00:00 2001
From: phenpessoa <phenpessoa@gmail.com>
Date: Mon, 13 Mar 2023 19:54:52 -0300
Subject: [PATCH] benchfmt: return an error in case of a non UTF-8 encoded file
 Currently, when using the benchstat tool to read files that are not UTF-8
 encoded, it will fail silently. With this patch, when parsing non UTF-8
 encoded files, benchfmt will now return an error instead letting the user
 know their input file is not properly formatted.

Fixes https://github.com/golang/go/issues/58579
---
 benchfmt/reader.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/benchfmt/reader.go b/benchfmt/reader.go
index 32b0ec6..6a84631 100644
--- a/benchfmt/reader.go
+++ b/benchfmt/reader.go
@@ -149,6 +149,11 @@ func (r *Reader) Scan() bool {
 		r.result.line++
 		// We do everything in byte buffers to avoid allocation.
 		line := r.s.Bytes()
+		// We only accept utf-8 encoded files.
+		if !utf8.Valid(line) {
+			r.err = fmt.Errorf("%s: invalid encode, only utf-8 encoded files are supported", r.result.fileName)
+			return false
+		}
 		// Most lines are benchmark lines, and we can check
 		// for that very quickly, so start with that.
 		if bytes.HasPrefix(line, benchmarkPrefix) {