Fix menu URL when multiple permalinkable output formats

In Hugo `0.55` we introduced the `permalinkable` config attribute on Output Format, default enabled for `AMP` and `HTML`.

This meant that a Page could have different `RelPermalink` and `Permalink` depending on the rendering format.

The menu `URL` did not reflect that fact.

Fixes #5849

4 files changed, 105 insertions, 32 deletions

diff --git a/hugolib/menu_test.go b/hugolib/menu_test.go
index 5c692d2e7..f1db3cb3a 100644
--- a/hugolib/menu_test.go
+++ b/hugolib/menu_test.go
@@ -92,10 +92,10 @@ Menu Main:  {{ partial "menu.html" (dict "page" . "menu" "main") }}`,
 
 	th.assertFileContent("public/sect1/p1/index.html", "Single",
 		"Menu Sect:  "+
-			"/sect5/|Section Five||10|-|-|"+
-			"/sect1/|Section One||100|-|HasMenuCurrent|"+
-			"/sect2/|Sect2s||0|-|-|"+
-			"/sect3/|Sect3s||0|-|-|",
+			"/sect5/|Section Five|Section Five|10|-|-|"+
+			"/sect1/|Section One|Section One|100|-|HasMenuCurrent|"+
+			"/sect2/|Sect2s|Sect2s|0|-|-|"+
+			"/sect3/|Sect3s|Sect3s|0|-|-|",
 		"Menu Main:  "+
 			"/sect3/p5/|p5|atitle5|5|-|-|"+
 			"/sect2/p4/|p4|atitle4|10|-|-|"+
@@ -106,10 +106,10 @@ Menu Main:  {{ partial "menu.html" (dict "page" . "menu" "main") }}`,
 
 	th.assertFileContent("public/sect2/p3/index.html", "Single",
 		"Menu Sect:  "+
-			"/sect5/|Section Five||10|-|-|"+
-			"/sect1/|Section One||100|-|-|"+
-			"/sect2/|Sect2s||0|-|HasMenuCurrent|"+
-			"/sect3/|Sect3s||0|-|-|")
+			"/sect5/|Section Five|Section Five|10|-|-|"+
+			"/sect1/|Section One|Section One|100|-|-|"+
+			"/sect2/|Sect2s|Sect2s|0|-|HasMenuCurrent|"+
+			"/sect3/|Sect3s|Sect3s|0|-|-|")
 
 }
 
@@ -163,3 +163,62 @@ menu:
 	)
 
 }
+
+// https://github.com/gohugoio/hugo/issues/5849
+func TestMenuPageMultipleOutputFormats(t *testing.T) {
+
+	config := `
+baseURL = "https://example.com"
+
+# DAMP is similar to AMP, but not permalinkable.
+[outputFormats]
+[outputFormats.damp]
+mediaType = "text/html"
+path = "damp"
+
+`
+
+	b := newTestSitesBuilder(t).WithConfigFile("toml", config)
+	b.WithContent("_index.md", `
+---
+Title: Home Sweet Home
+outputs: [ "html", "amp" ]
+menu: "main"
+---
+
+`)
+
+	b.WithContent("blog/html-amp.md", `
+---
+Title: AMP and HTML
+outputs: [ "html", "amp" ]
+menu: "main"
+---
+
+`)
+
+	b.WithContent("blog/html.md", `
+---
+Title: HTML only
+outputs: [ "html" ]
+menu: "main"
+---
+
+`)
+
+	b.WithContent("blog/amp.md", `
+---
+Title: AMP only
+outputs: [ "amp" ]
+menu: "main"
+---
+
+`)
+
+	b.WithTemplatesAdded("index.html", `{{ range .Site.Menus.main }}{{ .Title }}|{{ .URL }}|{{ end }}`)
+
+	b.Build(BuildCfg{})
+
+	b.AssertFileContent("public/index.html", "AMP and HTML|/blog/html-amp/|AMP only|/amp/blog/amp/|HTML only|/blog/html/|Home Sweet Home|/|")
+	b.AssertFileContent("public/amp/index.html", "AMP and HTML|/amp/blog/html-amp/|AMP only|/amp/blog/amp/|HTML only|/blog/html/|Home Sweet Home|/amp/|")
+}
diff --git a/hugolib/site.go b/hugolib/site.go
index 693c79f67..495225093 100644
--- a/hugolib/site.go
+++ b/hugolib/site.go
@@ -1416,7 +1416,8 @@ func (s *Site) getMenusFromConfig() navigation.Menus {
 					}
 
 					menuEntry.MarshallMap(ime)
-					menuEntry.URL = s.Info.createNodeMenuEntryURL(menuEntry.URL)
+					// TODO(bep) clean up all of this
+					menuEntry.ConfiguredURL = s.Info.createNodeMenuEntryURL(menuEntry.ConfiguredURL)
 
 					if ret[name] == nil {
 						ret[name] = navigation.Menu{}
@@ -1477,7 +1478,7 @@ func (s *Site) assembleMenus() {
 				me := navigation.MenuEntry{Identifier: id,
 					Name:   p.LinkTitle(),
 					Weight: p.Weight(),
-					URL:    p.RelPermalink()}
+					Page:   p}
 				flat[twoD{sectionPagesMenu, me.KeyName()}] = &me
 			}
 		}
@@ -1506,7 +1507,7 @@ func (s *Site) assembleMenus() {
 		_, ok := flat[twoD{p.MenuName, p.EntryName}]
 		if !ok {
 			// if parent does not exist, create one without a URL
-			flat[twoD{p.MenuName, p.EntryName}] = &navigation.MenuEntry{Name: p.EntryName, URL: ""}
+			flat[twoD{p.MenuName, p.EntryName}] = &navigation.MenuEntry{Name: p.EntryName}
 		}
 		flat[twoD{p.MenuName, p.EntryName}].Children = childmenu
 	}
diff --git a/navigation/menu.go b/navigation/menu.go
index 66721ea8a..47d40a3c7 100644
--- a/navigation/menu.go
+++ b/navigation/menu.go
@@ -14,6 +14,8 @@
 package navigation
 
 import (
+	"github.com/gohugoio/hugo/common/types"
+
 	"html/template"
 	"sort"
 	"strings"
@@ -24,17 +26,29 @@ import (
 // MenuEntry represents a menu item defined in either Page front matter
 // or in the site config.
 type MenuEntry struct {
-	URL        string
-	Page       Page
-	Name       string
-	Menu       string
-	Identifier string
-	title      string
-	Pre        template.HTML
-	Post       template.HTML
-	Weight     int
-	Parent     string
-	Children   Menu
+	ConfiguredURL string // The URL value from front matter / config.
+	Page          Page
+	Name          string
+	Menu          string
+	Identifier    string
+	title         string
+	Pre           template.HTML
+	Post          template.HTML
+	Weight        int
+	Parent        string
+	Children      Menu
+}
+
+func (m *MenuEntry) URL() string {
+	if m.ConfiguredURL != "" {
+		return m.ConfiguredURL
+	}
+
+	if !types.IsNil(m.Page) {
+		return m.Page.RelPermalink()
+	}
+
+	return ""
 }
 
 // A narrow version of page.Page.
@@ -72,8 +86,8 @@ func (m *MenuEntry) KeyName() string {
 func (m *MenuEntry) hopefullyUniqueID() string {
 	if m.Identifier != "" {
 		return m.Identifier
-	} else if m.URL != "" {
-		return m.URL
+	} else if m.URL() != "" {
+		return m.URL()
 	} else {
 		return m.Name
 	}
@@ -87,7 +101,8 @@ func (m *MenuEntry) IsEqual(inme *MenuEntry) bool {
 // IsSameResource returns whether the two menu entries points to the same
 // resource (URL).
 func (m *MenuEntry) IsSameResource(inme *MenuEntry) bool {
-	return m.URL != "" && inme.URL != "" && m.URL == inme.URL
+	murl, inmeurl := m.URL(), inme.URL()
+	return murl != "" && inmeurl != "" && murl == inmeurl
 }
 
 func (m *MenuEntry) MarshallMap(ime map[string]interface{}) {
@@ -95,7 +110,7 @@ func (m *MenuEntry) MarshallMap(ime map[string]interface{}) {
 		loki := strings.ToLower(k)
 		switch loki {
 		case "url":
-			m.URL = cast.ToString(v)
+			m.ConfiguredURL = cast.ToString(v)
 		case "weight":
 			m.Weight = cast.ToInt(v)
 		case "name":
diff --git a/navigation/pagemenus.go b/navigation/pagemenus.go
index c0d809ee3..4d2c45767 100644
--- a/navigation/pagemenus.go
+++ b/navigation/pagemenus.go
@@ -50,9 +50,7 @@ func PageMenusFromPage(p Page) (PageMenus, error) {
 		return nil, nil
 	}
 
-	link := p.RelPermalink()
-
-	me := MenuEntry{Page: p, Name: p.LinkTitle(), Weight: p.Weight(), URL: link}
+	me := MenuEntry{Page: p, Name: p.LinkTitle(), Weight: p.Weight()}
 
 	// Could be the name of the menu to attach it to
 	mname, err := cast.ToStringE(ms)
@@ -81,7 +79,7 @@ func PageMenusFromPage(p Page) (PageMenus, error) {
 	}
 
 	for name, menu := range menus {
-		menuEntry := MenuEntry{Page: p, Name: p.LinkTitle(), URL: link, Weight: p.Weight(), Menu: name}
+		menuEntry := MenuEntry{Page: p, Name: p.LinkTitle(), Weight: p.Weight(), Menu: name}
 		if menu != nil {
 			ime, err := cast.ToStringMapE(menu)
 			if err != nil {
@@ -153,7 +151,7 @@ func (pm *pageMenus) HasMenuCurrent(menuID string, me *MenuEntry) bool {
 
 	// The following logic is kept from back when Hugo had both Page and Node types.
 	// TODO(bep) consolidate / clean
-	nme := MenuEntry{Page: pm.p, Name: pm.p.LinkTitle(), URL: pm.p.RelPermalink()}
+	nme := MenuEntry{Page: pm.p, Name: pm.p.LinkTitle()}
 
 	for _, child := range me.Children {
 		if nme.IsSameResource(child) {
@@ -183,7 +181,7 @@ func (pm *pageMenus) IsMenuCurrent(menuID string, inme *MenuEntry) bool {
 
 	// The following logic is kept from back when Hugo had both Page and Node types.
 	// TODO(bep) consolidate / clean
-	me := MenuEntry{Page: pm.p, Name: pm.p.LinkTitle(), URL: pm.p.RelPermalink()}
+	me := MenuEntry{Page: pm.p, Name: pm.p.LinkTitle()}
 
 	if !me.IsSameResource(inme) {
 		return false