langs: Use Language.Locale as primary localization key

Localization now uses Language.Locale as the golocales lookup key,
falling back to Language.Lang, then defaultContentLanguage, then "en".

Closes #9109

diff --git a/langs/language.go b/langs/language.go
index 1ff15b2663785585949979307b115141eb8f4ecc..fc33518b1e2d96cd442d35eda2ee36c2682cd058 100644 (file)
--- a/langs/language.go
+++ b/langs/language.go
@@ -79,11 +79,13 @@ func (l *Language) IsDefault() bool {
 
 // NewLanguage creates a new language.
 func NewLanguage(lang, defaultContentLanguage, timeZone string, languageConfig LanguageConfig, logger loggers.Logger) (*Language, error) {
-       translator := golocales.New(lang)
-       if translator == nil {
-               translator = golocales.New(defaultContentLanguage)
-               if translator == nil {
-                       translator = golocales.New("en")
+       var translator golocales.Translator
+       for _, key := range []string{languageConfig.Locale, lang, defaultContentLanguage, "en"} {
+               if key == "" {
+                       continue
+               }
+               if translator = golocales.New(key); translator != nil {
+                       break
                }
        }
 

diff --git a/langs/languages_integration_test.go b/langs/languages_integration_test.go
index 20b93e0f95ddcc00e175fa144c9c77a956f6e402..5e58cdc8c559f1b3085aef25ef576445531e893c 100644 (file)
--- a/langs/languages_integration_test.go
+++ b/langs/languages_integration_test.go
@@ -215,3 +215,84 @@ TITLE: {{ .Title }} RELPERMALINK: {{ .RelPermalink }}|
                "b (en)|TITLE: P1 (en) RELPERMALINK: /en/p1/|",
        )
 }
+
+func TestLocaleAsLocalizationKeyIssue9109(t *testing.T) {
+       t.Parallel()
+
+       files := `
+-- hugo.toml --
+disableKinds = ['page','rss','section','sitemap','taxonomy','term']
+defaultContentLanguage = 'de'
+defaultContentLanguageInSubdir = true
+
+[languages.de]
+weight = 1
+
+[languages.en]
+locale = 'en-US'
+weight = 2
+
+[languages.fr]
+locale = 'bogus'
+weight = 3
+
+[languages.nn]
+weight = 4
+
+[languages.xx]
+locale = 'bogus'
+weight = 5
+
+[languages.zh-cn]
+locale = 'zh-Hans'
+weight = 6
+-- layouts/home.html --
+Time: {{ "2026-04-01T20:11:31+08:00" | time.Format ":date_long" }}|
+FormatAccounting: {{ 512.5032 | lang.FormatAccounting 2 "USD" }}|
+FormatCurrency: {{ 512.5032 | lang.FormatCurrency 2 "USD" }}|
+`
+
+       b := hugolib.Test(t, files)
+
+       // de: no locale => localize with lang.
+       b.AssertFileContent("public/de/index.html",
+               `Time: 1. April 2026|`,
+               "FormatAccounting: 512,50\u00a0$|",
+               "FormatCurrency: 512,50\u00a0$|",
+       )
+
+       // en: valid locale => localize with locale.
+       b.AssertFileContent("public/en/index.html",
+               `Time: April 1, 2026|`,
+               `FormatAccounting: $512.50|`,
+               `FormatCurrency: $512.50|`,
+       )
+
+       // fr: invalid locale => localize with lang.
+       b.AssertFileContent("public/fr/index.html",
+               `Time: 1 avril 2026|`,
+               "FormatAccounting: 512,50\u00a0$US|",
+               "FormatCurrency: 512,50\u00a0$US|",
+       )
+
+       // nn: no locale => localize with lang.
+       b.AssertFileContent("public/nn/index.html",
+               `Time: 1. april 2026|`,
+               "FormatAccounting: 512,50\u00a0USD|",
+               "FormatCurrency: 512,50\u00a0USD|",
+       )
+
+       // xx: invalid locale + invalid lang => localize with defaultContentLanguage.
+       b.AssertFileContent("public/xx/index.html",
+               `Time: 1. April 2026|`,
+               "FormatAccounting: 512,50\u00a0$|",
+               "FormatCurrency: 512,50\u00a0$|",
+       )
+
+       // zh-cn: invalid lang, but valid locale => localize with locale.
+       b.AssertFileContent("public/zh-cn/index.html",
+               `Time: 2026年4月1日|`,
+               `FormatAccounting: US$512.50|`,
+               `FormatCurrency: US$512.50|`,
+       )
+}