Assign LazyContentProvider in shiftToOutputFormat

In response to PR feedback to keep all content reuse logic in
shiftToOutputFormat

hugolib/page.go

@@ -940,6 +940,20 @@ func (p *pageState) shiftToOutputFormat(isRenderingSite bool, idx int) error {
 		panic(fmt.Sprintf("pageOutput is nil for output idx %d", idx))
 	}
 
+	// We attempt to assign pageContentOutputs while preparing each site
+	// for rendering and before rendering each site. This lets us share
+	// content between page outputs to conserve resources. But if a template
+	// unexpectedly calls a method of a ContentProvider that is not yet
+	// initialized, we assign a LazyContentProvider that performs the
+	// initialization just in time.
+	p.pageOutput.ContentProvider = page.NewLazyContentProvider(func() (page.ContentProvider, error) {
+		cp, err := newPageContentOutput(p, p.pageOutput)
+		if err != nil {
+			return nil, err
+		}
+		return cp, nil
+	})
+
 	// Reset any built paginator. This will trigger when re-rendering pages in
 	// server mode.
 	if isRenderingSite && p.pageOutput.paginator != nil && p.pageOutput.paginator.current != nil {

hugolib/page__output.go

@@ -55,21 +55,9 @@ func newPageOutput(
 	}
 
 	po := &pageOutput{
-		f:                      f,
-		pagePerOutputProviders: providers,
-		// We attempt to assign pageContentOutputs while preparing each site
-		// for rendering and before rendering each site. This lets us share
-		// content between page outputs and conserve resources. However, this
-		// does not guarantee that all pageContentOutputs required by templates
-		// will be assigned. In the case of an unanticipated request, we lazily
-		// initialize a pageContentOutput.
-		ContentProvider: page.NewLazyContentProvider(func() (page.ContentProvider, error) {
-			cp, err := newPageContentOutput(ps, ps.pageOutput)
-			if err != nil {
-				return nil, err
-			}
-			return cp, nil
-		}),
+		f:                       f,
+		pagePerOutputProviders:  providers,
+		ContentProvider:         page.NopPage,
 		TableOfContentsProvider: page.NopPage,
 		render:                  render,
 		paginator:               pag,