From e6f4a3cdf322be2d95e4d8c7fee9dbbdbef733b8 Mon Sep 17 00:00:00 2001
From: Eric Gallager <egall@gwmail.gwu.edu>
Date: Sun, 22 Sep 2024 03:25:27 -0400
Subject: [PATCH] Fix code scanning alert #23: Incorrect conversion between
 integer types

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>
---
 libgo/go/go/scanner/scanner.go | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/libgo/go/go/scanner/scanner.go b/libgo/go/go/scanner/scanner.go
index 23d8db9d1ccdf..5ef60bca85abd 100644
--- a/libgo/go/go/scanner/scanner.go
+++ b/libgo/go/go/scanner/scanner.go
@@ -16,6 +16,7 @@ import (
 	"strconv"
 	"unicode"
 	"unicode/utf8"
+	"math"
 )
 
 // An ErrorHandler may be provided to Scanner.Init. If a syntax error is
@@ -296,8 +297,11 @@ func trailingDigits(text []byte) (int, int, bool) {
 		return 0, 0, false // no ":"
 	}
 	// i >= 0
-	n, err := strconv.ParseUint(string(text[i+1:]), 10, 0)
-	return i + 1, int(n), err == nil
+	n, err := strconv.ParseUint(string(text[i+1:]), 10, 32)
+	if err != nil || n > math.MaxInt32 {
+		return 0, 0, false
+	}
+	return i + 1, int(n), true
 }
 
 func (s *Scanner) findLineEnd() bool {