snapshot of https://github.com/go-gitea/gitea.git (main, 2026-09-15; blobs > 131072B omitted)

modules/web/middleware/locale_test.go

@@ -0,0 +1,27 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package middleware
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseAcceptLanguage(t *testing.T) {
+	// a normal header is parsed and its leading language preserved
+	tags := parseAcceptLanguage("de-DE,de;q=0.9,en;q=0.8")
+	assert.NotEmpty(t, tags)
+	assert.Equal(t, "de-DE", tags[0].String())
+
+	// an oversized "_"-separated header would drive ParseAcceptLanguage into its
+	// quadratic-time path (the built-in guard only counts "-"); the length bound
+	// keeps the input passed to the parser small so it cannot be used for a DoS.
+	malicious := strings.Repeat("_aaaaaaaaa", 1<<16) // ~640 KiB, zero "-" characters
+	assert.Greater(t, len(malicious), maxAcceptLanguageLen)
+	tags = parseAcceptLanguage(malicious)
+	// no panic / hang, and nothing meaningful is parsed out of the garbage
+	assert.Empty(t, tags)
+}