Fix multiple languages in HUGO_DISABLELANGUAGES

Fixes #11278

config/allconfig/load.go

@@ -297,21 +297,41 @@ func (l configLoader) applyOsEnvOverrides(environ []string) error {
 			if nestedKey != "" {
 				owner[nestedKey] = env.Value
 			} else {
-				var val any = env.Value
-				if _, ok := allDecoderSetups[env.Key]; ok {
+				var val any
+				key := strings.ReplaceAll(env.Key, delim, ".")
+				_, ok := allDecoderSetups[key]
+				if ok {
 					// A map.
-					val, err = metadecoders.Default.UnmarshalStringTo(env.Value, map[string]interface{}{})
+					if v, err := metadecoders.Default.UnmarshalStringTo(env.Value, map[string]interface{}{}); err == nil {
+						val = v
+					}
 				}
-				if err == nil {
-					l.cfg.Set(strings.ReplaceAll(env.Key, delim, "."), val)
+				if val == nil {
+					// A string.
+					val = l.envStringToVal(key, env.Value)
 				}
+				l.cfg.Set(key, val)
 			}
 		}
 	}
 
 	return nil
 }
 
+func (l *configLoader) envStringToVal(k, v string) any {
+	switch k {
+	case "disablekinds", "disablelanguages":
+		if strings.Contains(v, ",") {
+			return strings.Split(v, ",")
+		} else {
+			return strings.Fields(v)
+		}
+	default:
+		return v
+	}
+
+}
+
 func (l *configLoader) loadConfigMain(d ConfigSourceDescriptor) (config.LoadConfigResult, modules.ModulesConfig, error) {
 	var res config.LoadConfigResult
 

hugolib/config_test.go

@@ -259,6 +259,47 @@ sub: map[sub1:sub1en]
 
 }
 
+func TestDisableRootSlicesFromEnv(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- hugo.toml --
+baseURL = "https://example.com"
+defaultContentLanguage = "en"
+defaultContentLanguageInSubdir = true
+[languages]
+[languages.en]
+weight = 1
+[languages.sv]
+weight = 2
+[languages.no]
+weight = 3
+
+-- layouts/index.html --
+Home.
+`
+
+	for _, delim := range []string{" ", ","} {
+		environ := []string{"HUGO_DISABLELANGUAGES=sv no", "HUGO_DISABLEKINDS=taxonomy term"}
+		for i, v := range environ {
+			environ[i] = strings.ReplaceAll(v, " ", delim)
+		}
+		b := NewIntegrationTestBuilder(
+			IntegrationTestConfig{
+				T:           t,
+				TxtarString: files,
+				Environ:     environ,
+				BuildCfg:    BuildCfg{SkipRender: true},
+			},
+		).Build()
+
+		conf := b.H.Configs.Base
+		b.Assert(conf.DisableLanguages, qt.DeepEquals, []string{"sv", "no"})
+		b.Assert(conf.DisableKinds, qt.DeepEquals, []string{"taxonomy", "term"})
+	}
+
+}
+
 func TestLoadMultiConfig(t *testing.T) {
 	t.Parallel()