Avoid nilpointer on no File on Page

Fixes #5781

resources/page/zero_file.autogen.go

@@ -0,0 +1,88 @@
+// Copyright 2019 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This file is autogenerated.
+
+package page
+
+import (
+	"github.com/gohugoio/hugo/helpers"
+	"github.com/gohugoio/hugo/source"
+	"os"
+)
+
+// ZeroFile represents a zero value of source.File with warnings if invoked.
+type zeroFile struct {
+	log *helpers.DistinctLogger
+}
+
+func NewZeroFile(log *helpers.DistinctLogger) source.File {
+	return zeroFile{log: log}
+}
+
+func (zeroFile) IsZero() bool {
+	return true
+}
+
+func (z zeroFile) Path() (o0 string) {
+	z.log.Println(".File.Path on zero object. Wrap it in if or with: {{ with .File }}{{ .Path }}{{ end }}")
+	return
+}
+func (z zeroFile) Section() (o0 string) {
+	z.log.Println(".File.Section on zero object. Wrap it in if or with: {{ with .File }}{{ .Section }}{{ end }}")
+	return
+}
+func (z zeroFile) Lang() (o0 string) {
+	z.log.Println(".File.Lang on zero object. Wrap it in if or with: {{ with .File }}{{ .Lang }}{{ end }}")
+	return
+}
+func (z zeroFile) Filename() (o0 string) {
+	z.log.Println(".File.Filename on zero object. Wrap it in if or with: {{ with .File }}{{ .Filename }}{{ end }}")
+	return
+}
+func (z zeroFile) Dir() (o0 string) {
+	z.log.Println(".File.Dir on zero object. Wrap it in if or with: {{ with .File }}{{ .Dir }}{{ end }}")
+	return
+}
+func (z zeroFile) Extension() (o0 string) {
+	z.log.Println(".File.Extension on zero object. Wrap it in if or with: {{ with .File }}{{ .Extension }}{{ end }}")
+	return
+}
+func (z zeroFile) Ext() (o0 string) {
+	z.log.Println(".File.Ext on zero object. Wrap it in if or with: {{ with .File }}{{ .Ext }}{{ end }}")
+	return
+}
+func (z zeroFile) LogicalName() (o0 string) {
+	z.log.Println(".File.LogicalName on zero object. Wrap it in if or with: {{ with .File }}{{ .LogicalName }}{{ end }}")
+	return
+}
+func (z zeroFile) BaseFileName() (o0 string) {
+	z.log.Println(".File.BaseFileName on zero object. Wrap it in if or with: {{ with .File }}{{ .BaseFileName }}{{ end }}")
+	return
+}
+func (z zeroFile) TranslationBaseName() (o0 string) {
+	z.log.Println(".File.TranslationBaseName on zero object. Wrap it in if or with: {{ with .File }}{{ .TranslationBaseName }}{{ end }}")
+	return
+}
+func (z zeroFile) ContentBaseName() (o0 string) {
+	z.log.Println(".File.ContentBaseName on zero object. Wrap it in if or with: {{ with .File }}{{ .ContentBaseName }}{{ end }}")
+	return
+}
+func (z zeroFile) UniqueID() (o0 string) {
+	z.log.Println(".File.UniqueID on zero object. Wrap it in if or with: {{ with .File }}{{ .UniqueID }}{{ end }}")
+	return
+}
+func (z zeroFile) FileInfo() (o0 os.FileInfo) {
+	z.log.Println(".File.FileInfo on zero object. Wrap it in if or with: {{ with .File }}{{ .FileInfo }}{{ end }}")
+	return
+}