langs/i18n: Fix translation lookup when using language variants

jmooring · claude · bep · commit 72b85d5f9c2d · 2026-04-23T18:47:12.000+02:00
Closes #7982 Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
diff --git a/langs/i18n/translationProvider.go b/langs/i18n/translationProvider.go
@@ -17,6 +17,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"sort"
 	"strings"
 
 	"github.com/gohugoio/hugo/common/paths"
@@ -59,6 +60,7 @@ func (tp *TranslationProvider) NewResource(dst *deps.Deps) error {
 	bundle.RegisterUnmarshalFunc("yml", metadecoders.UnmarshalYaml)
 	bundle.RegisterUnmarshalFunc("json", json.Unmarshal)
 
+	var files []hugofs.FileMetaInfo
 	w := hugofs.NewWalkway(
 		hugofs.WalkwayConfig{
 			Fs:         dst.BaseFs.I18n.Fs,
@@ -68,14 +70,30 @@ func (tp *TranslationProvider) NewResource(dst *deps.Deps) error {
 				if info.IsDir() {
 					return nil
 				}
-				return addTranslationFile(bundle, source.NewFileInfo(info))
+				files = append(files, info)
+				return nil
 			},
 		})
 
 	if err := w.Walk(); err != nil {
 		return err
 	}
 
+	// Sort translation files so that base tags (e.g. "de") are always registered
+	// before their subtag variants (e.g. "de-DE"); without this ordering the
+	// fallback chain breaks. See https://github.com/gohugoio/hugo/issues/7982.
+	sort.Slice(files, func(i, j int) bool {
+		si := files[i].Meta().PathInfo.NameNoExt()
+		sj := files[j].Meta().PathInfo.NameNoExt()
+		return strings.Count(si, "-") < strings.Count(sj, "-")
+	})
+
+	for _, info := range files {
+		if err := addTranslationFile(bundle, source.NewFileInfo(info)); err != nil {
+			return err
+		}
+	}
+
 	tp.t = NewTranslator(bundle, dst.Conf, dst.Log)
 
 	dst.Translate = tp.getTranslateFunc(dst)
diff --git a/langs/languages_integration_test.go b/langs/languages_integration_test.go
@@ -296,3 +296,33 @@ FormatCurrency: {{ 512.5032 | lang.FormatCurrency 2 "USD" }}|
 		`FormatCurrency: US$512.50|`,
 	)
 }
+
+func TestMultipleLanguageVariants7982(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- hugo.toml --
+disableKinds = ['page','section','rss','sitemap','taxonomy','term']
+defaultContentLanguageInSubdir = true
+[languages.en]
+weight = 1
+[languages.de]
+weight = 2
+[languages.de-de]
+weight = 3
+-- i18n/en.toml --
+file = 'en'
+-- i18n/de.toml --
+file = 'de'
+-- i18n/de-de.toml --
+file = 'de-de'
+-- layouts/index.html --
+language: {{ site.Language.Name }} file: {{ T "file" }}|
+`
+
+	b := hugolib.Test(t, files)
+
+	b.AssertFileContent("public/en/index.html", "language: en file: en|")
+	b.AssertFileContent("public/de/index.html", "language: de file: de|")
+	b.AssertFileContent("public/de-de/index.html", "language: de-de file: de-de|")
+}
