hugolib: Fix bundle resource publishing when multiple output formats

The faulty logic published the bundled resources for the "first output" format.

This worked most of the time, but since the output formats list is sorted,
any output format only used for some of the pages (e.g. CSS) would not work properly.

Fixes #5858

hugolib/page.go

@@ -360,7 +360,8 @@ func (p *pageState) setPages(pages page.Pages) {
 	p.pages = pages
 }
 
-func (p *pageState) renderResources() error {
+func (p *pageState) renderResources() (err error) {
+	p.resourcesPublishInit.Do(func() {
 		var toBeDeleted []int
 
 		for i, r := range p.Resources() {
@@ -372,7 +373,8 @@ func (p *pageState) renderResources() error {
 
 			src, ok := r.(resource.Source)
 			if !ok {
-			return errors.Errorf("Resource %T does not support resource.Source", src)
+				err = errors.Errorf("Resource %T does not support resource.Source", src)
+				return
 			}
 
 			if err := src.Publish(); err != nil {
@@ -393,7 +395,9 @@ func (p *pageState) renderResources() error {
 			p.deleteResource(i)
 		}
 
-	return nil
+	})
+
+	return
 }
 
 func (p *pageState) deleteResource(i int) {

hugolib/page__common.go

@@ -93,6 +93,7 @@ type pageCommon struct {
 	// Any bundled resources
 	resources            resource.Resources
 	resourcesInit        sync.Once
+	resourcesPublishInit sync.Once
 
 	translations    page.Pages
 	allTranslations page.Pages

hugolib/pagebundler_test.go

@@ -896,3 +896,37 @@ TheContent.
 
 	return ps, clean, workDir
 }
+
+// https://github.com/gohugoio/hugo/issues/5858
+func TestBundledResourcesWhenMultipleOutputFormats(t *testing.T) {
+	t.Parallel()
+
+	b := newTestSitesBuilder(t).Running().WithConfigFile("toml", `
+baseURL = "https://example.org"
+[outputs]
+  # This looks odd, but it triggers the behaviour in #5858
+  # The total output formats list gets sorted, so CSS before HTML.
+  home = [ "CSS" ]
+
+`)
+	b.WithContent("mybundle/index.md", `
+---
+title: Page
+date: 2017-01-15
+---
+`,
+		"mybundle/data.json", "MyData",
+	)
+
+	b.CreateSites().Build(BuildCfg{})
+
+	b.AssertFileContent("public/mybundle/data.json", "MyData")
+
+	// Change the bundled JSON file and make sure it gets republished.
+	b.EditFiles("content/mybundle/data.json", "My changed data")
+
+	b.Build(BuildCfg{})
+
+	b.AssertFileContent("public/mybundle/data.json", "My changed data")
+
+}

hugolib/shortcode_test.go

@@ -903,6 +903,7 @@ func TestShortcodeParentResourcesOnRebuild(t *testing.T) {
 	b.WithTemplatesAdded(
 		"index.html", `
 {{ $b := .Site.GetPage "b1" }}
+b1 Content: {{ $b.Content }}
 {{$p := $b.Resources.GetMatch "p1*" }}
 Content: {{ $p.Content }}
 {{ $article := .Site.GetPage "blog/article" }}
@@ -933,20 +934,23 @@ SHORTCODE: {{< c >}}
 
 	b.Build(BuildCfg{})
 
-	assert := func() {
-		b.AssertFileContent("public/index.html",
-			"Parent resource: logo.png: /b1/logo.png",
+	assert := func(matchers ...string) {
+		allMatchers := append(matchers, "Parent resource: logo.png: /b1/logo.png",
 			"Article Content: <p>SHORTCODE: \n\n* Parent resource: logo-article.png: /blog/logo-article.png",
 		)
+
+		b.AssertFileContent("public/index.html",
+			allMatchers...,
+		)
 	}
 
 	assert()
 
-	b.EditFiles("b1/index.md", pageContent+" Edit.")
+	b.EditFiles("content/b1/index.md", pageContent+" Edit.")
 
 	b.Build(BuildCfg{})
 
-	assert()
+	assert("Edit.")
 
 }
 

hugolib/site_render.go

@@ -35,6 +35,7 @@ type siteRenderContext struct {
 	sitesOutIdx int
 
 	// Zero based index of the output formats configured within a Site.
+	// Note that these outputs are sorted, so CSS will come before HTML.
 	outIdx int
 
 	multihost bool
@@ -130,12 +131,10 @@ func pageRenderer(
 			continue
 		}
 
-		if ctx.outIdx == 0 {
 		if err := p.renderResources(); err != nil {
 			s.SendError(p.errorf(err, "failed to render page resources"))
 			continue
 		}
-		}
 
 		layouts, err := p.getLayouts()
 		if err != nil {