Fix translationKey handling for term pages

Fixes #12261

hugolib/page_test.go

@@ -1350,6 +1350,51 @@ AllTranslations: {{ range .AllTranslations }}{{ .Language.Lang }}|{{ end }}|
 	)
 }
 
+func TestTranslationKeyTermPages(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- hugo.toml --
+disableKinds = ['home','rss','section','sitemap','taxonomy']
+defaultContentLanguage = 'en'
+defaultContentLanguageInSubdir = true
+[languages.en]
+weight = 1
+[languages.pt]
+weight = 2
+[taxonomies]
+category = 'categories'
+-- layouts/_default/list.html --
+{{ .IsTranslated }}|{{ range .Translations }}{{ .RelPermalink }}|{{ end }}
+-- layouts/_default/single.html --
+{{ .Title }}|
+-- content/p1.en.md --
+---
+title: p1 (en)
+categories: [music]
+---
+-- content/p1.pt.md --
+---
+title: p1 (pt)
+categories: [música]
+---
+-- content/categories/music/_index.en.md --
+---
+title: music
+translationKey: foo
+---
+-- content/categories/música/_index.pt.md --
+---
+title: música
+translationKey: foo
+---
+`
+
+	b := Test(t, files)
+	b.AssertFileContent("public/en/categories/music/index.html", "true|/pt/categories/m%C3%BAsica/|")
+	b.AssertFileContent("public/pt/categories/música/index.html", "true|/en/categories/music/|")
+}
+
 // Issue #11540.
 func TestTranslationKeyResourceSharing(t *testing.T) {
 	files := `