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

1 files changed, 31 insertions, 27 deletions

diff --git a/hugolib/page.go b/hugolib/page.go
index ec4b23d90..537482fb2 100644
--- a/hugolib/page.go
+++ b/hugolib/page.go
@@ -360,40 +360,44 @@ func (p *pageState) setPages(pages page.Pages) {
 	p.pages = pages
 }
 
-func (p *pageState) renderResources() error {
-	var toBeDeleted []int
-
-	for i, r := range p.Resources() {
-		if _, ok := r.(page.Page); ok {
-			// Pages gets rendered with the owning page but we count them here.
-			p.s.PathSpec.ProcessingStats.Incr(&p.s.PathSpec.ProcessingStats.Pages)
-			continue
-		}
+func (p *pageState) renderResources() (err error) {
+	p.resourcesPublishInit.Do(func() {
+		var toBeDeleted []int
+
+		for i, r := range p.Resources() {
+			if _, ok := r.(page.Page); ok {
+				// Pages gets rendered with the owning page but we count them here.
+				p.s.PathSpec.ProcessingStats.Incr(&p.s.PathSpec.ProcessingStats.Pages)
+				continue
+			}
 
-		src, ok := r.(resource.Source)
-		if !ok {
-			return errors.Errorf("Resource %T does not support resource.Source", src)
-		}
+			src, ok := r.(resource.Source)
+			if !ok {
+				err = errors.Errorf("Resource %T does not support resource.Source", src)
+				return
+			}
 
-		if err := src.Publish(); err != nil {
-			if os.IsNotExist(err) {
-				// The resource has been deleted from the file system.
-				// This should be extremely rare, but can happen on live reload in server
-				// mode when the same resource is member of different page bundles.
-				toBeDeleted = append(toBeDeleted, i)
+			if err := src.Publish(); err != nil {
+				if os.IsNotExist(err) {
+					// The resource has been deleted from the file system.
+					// This should be extremely rare, but can happen on live reload in server
+					// mode when the same resource is member of different page bundles.
+					toBeDeleted = append(toBeDeleted, i)
+				} else {
+					p.s.Log.ERROR.Printf("Failed to publish Resource for page %q: %s", p.pathOrTitle(), err)
+				}
 			} else {
-				p.s.Log.ERROR.Printf("Failed to publish Resource for page %q: %s", p.pathOrTitle(), err)
+				p.s.PathSpec.ProcessingStats.Incr(&p.s.PathSpec.ProcessingStats.Files)
 			}
-		} else {
-			p.s.PathSpec.ProcessingStats.Incr(&p.s.PathSpec.ProcessingStats.Files)
 		}
-	}
 
-	for _, i := range toBeDeleted {
-		p.deleteResource(i)
-	}
+		for _, i := range toBeDeleted {
+			p.deleteResource(i)
+		}
 
-	return nil
+	})
+
+	return
 }
 
 func (p *pageState) deleteResource(i int) {