Fix regression when config for OutputFormat.BaseName is an empty string

Fixes #11000

hugolib/config_test.go

@@ -1002,3 +1002,41 @@ Home
 	conf := b.H.Configs.Base
 	b.Assert(conf.IsKindEnabled("term"), qt.Equals, false)
 }
+
+// Issue #11000
+func TestConfigEmptyTOMLString(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- hugo.toml --
+[mediaTypes]
+[mediaTypes."text/htaccess"]
+suffixes = ["htaccess"]
+[outputFormats]
+[outputFormats.htaccess]
+mediaType = "text/htaccess"
+baseName = ""
+isPlainText = false
+notAlternative = true
+-- content/_index.md --
+---
+outputs: ["html", "htaccess"]
+---
+-- layouts/index.html --
+HTML.
+-- layouts/_default/list.htaccess --
+HTACCESS.
+
+
+	
+`
+	b := NewIntegrationTestBuilder(
+		IntegrationTestConfig{
+			T:           t,
+			TxtarString: files,
+		},
+	).Build()
+
+	b.AssertFileContent("public/.htaccess", "HTACCESS")
+
+}

output/config.go

@@ -32,6 +32,11 @@ type OutputFormatConfig struct {
 	Format
 }
 
+var defaultOutputFormat = Format{
+	BaseName: "index",
+	Rel:      "alternate",
+}
+
 func DecodeConfig(mediaTypes media.Types, in any) (*config.ConfigNamespace[map[string]OutputFormatConfig, Formats], error) {
 	buildConfig := func(in any) (Formats, any, error) {
 		f := make(Formats, len(DefaultFormats))
@@ -59,20 +64,12 @@ func DecodeConfig(mediaTypes media.Types, in any) (*config.ConfigNamespace[map[s
 					continue
 				}
 
-				var newOutFormat Format
+				newOutFormat := defaultOutputFormat
 				newOutFormat.Name = k
 				if err := decode(mediaTypes, v, &newOutFormat); err != nil {
 					return f, nil, err
 				}
 
-				// We need values for these
-				if newOutFormat.BaseName == "" {
-					newOutFormat.BaseName = "index"
-				}
-				if newOutFormat.Rel == "" {
-					newOutFormat.Rel = "alternate"
-				}
-
 				f = append(f, newOutFormat)
 
 			}