Don't auto-create empty sections for nested taxonomies

Fixes #12188

hugolib/content_map_page.go

@@ -1814,6 +1814,14 @@ func (sa *sitePagesAssembler) addMissingRootSections() error {
 				return false, nil
 			}
 
+			switch ps.Kind() {
+			case kinds.KindPage, kinds.KindSection:
+				// OK
+			default:
+				// Skip taxonomy nodes etc.
+				return false, nil
+			}
+
 			p := ps.m.pathInfo
 			section := p.Section()
 			if section == "" || seen[section] {

hugolib/taxonomy_test.go

@@ -936,3 +936,37 @@ title: Authors Page
 	b.AssertFileExists("public/authors/index.html", true)
 	b.AssertFileContent("public/authors/index.html", "layouts/_default/author.terms.html") // failing test
 }
+
+func TestTaxonomyNestedEmptySectionsIssue12188(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- hugo.toml --
+disableKinds = ['rss','sitemap']
+defaultContentLanguage = 'en'
+defaultContentLanguageInSubdir = true
+[languages.en]
+weight = 1
+[languages.ja]
+weight = 2
+[taxonomies]
+'s1/category' = 's1/category'
+-- layouts/_default/single.html --
+{{ .Title }}|
+-- layouts/_default/list.html --
+{{ .Title }}|
+-- content/s1/p1.en.md --
+---
+title: p1
+---
+`
+
+	b := Test(t, files)
+
+	b.AssertFileExists("public/en/s1/index.html", true)
+	b.AssertFileExists("public/en/s1/p1/index.html", true)
+	b.AssertFileExists("public/en/s1/category/index.html", true)
+
+	b.AssertFileExists("public/ja/s1/index.html", false) // failing test
+	b.AssertFileExists("public/ja/s1/category/index.html", true)
+}