From 0864d04c5c7d8425de479a1a03f8c6e360bac427 Mon Sep 17 00:00:00 2001
From: greatroar <61184462+greatroar@users.noreply.github.com>
Date: Thu, 4 Sep 2025 11:23:05 +0200
Subject: [PATCH] internal/restic: Fix panic in ParseDuration

Fixes #5485. Includes test case by @MichaelEischer.
---
 internal/restic/duration.go      | 3 +--
 internal/restic/duration_test.go | 4 ++++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/internal/restic/duration.go b/internal/restic/duration.go
index 831971fe0..6ab4c3c79 100644
--- a/internal/restic/duration.go
+++ b/internal/restic/duration.go
@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
-	"unicode"
 
 	"github.com/restic/restic/internal/errors"
 )
@@ -52,7 +51,7 @@ func nextNumber(input string) (num int, rest string, err error) {
 	}
 
 	for i, s := range input {
-		if !unicode.IsNumber(s) {
+		if s < '0' || s > '9' {
 			rest = input[i:]
 			break
 		}
diff --git a/internal/restic/duration_test.go b/internal/restic/duration_test.go
index f03aa5553..c5f0390db 100644
--- a/internal/restic/duration_test.go
+++ b/internal/restic/duration_test.go
@@ -37,6 +37,9 @@ func TestNextNumber(t *testing.T) {
 		{
 			input: "5d  ", num: 5, rest: "d  ",
 		},
+		{
+			input: "5", num: 5, rest: "",
+		},
 	}
 
 	for _, test := range tests {
@@ -78,6 +81,7 @@ func TestParseDuration(t *testing.T) {
 		{input: "2w", err: true},
 		{input: "1y4m3w1d", err: true},
 		{input: "s", err: true},
+		{input: "\xdf\x80", err: true}, // NKO DIGIT ZERO; we want ASCII digits
 	}
 
 	for _, test := range tests {