Fix .Fragments when called cross sites on uninitialized output format

Fixes #10794

hugolib/page__fragments_test.go

@@ -0,0 +1,69 @@
+// Copyright 2023 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package hugolib
+
+import "testing"
+
+// #10794
+func TestFragmentsAndToCCrossSiteAccess(t *testing.T) {
+	files := `
+-- hugo.toml --
+baseURL = "https://example.com"
+disableKinds = ["taxonomy", "term", "home"]
+defaultContentLanguage = "en"
+defaultContentLanguageInSubdir = true
+[languages]
+[languages.en]
+weight = 1
+[languages.fr]
+weight = 2
+-- content/p1.en.md --
+---
+title: "P1"
+outputs: ["HTML", "JSON"]
+---
+
+## Heading 1 EN
+
+-- content/p1.fr.md --
+---
+title: "P1"
+outputs: ["HTML", "JSON"]
+---
+
+## Heading 1 FR
+-- layouts/_default/single.html --
+HTML
+-- layouts/_default/single.json --
+{{ $secondSite := index .Sites 1 }}
+{{ $p1 := $secondSite.GetPage "p1" }}
+ToC: {{ $p1.TableOfContents }}
+Fragments : {{ $p1.Fragments.Identifiers }}
+
+
+
+	
+`
+
+	b := NewIntegrationTestBuilder(
+		IntegrationTestConfig{
+			TxtarString: files,
+			T:           t,
+		},
+	).Build()
+
+	b.AssertFileContent("public/en/p1/index.html", "HTML")
+	b.AssertFileContent("public/en/p1/index.json", "ToC: <nav id=\"TableOfContents\">\n  <ul>\n    <li><a href=\"#heading-1-fr\">Heading 1 FR</a></li>\n  </ul>\n</nav>\nFragments : [heading-1-fr]")
+
+}