Misc paginator adjustments

* Rewind paginator for server mode
* Add some more related tests.
* Replace the clumsy scratch constructs in internal paginator template with variables

See #5825

5 files changed, 121 insertions, 13 deletions

diff --git a/hugolib/page__paginator.go b/hugolib/page__paginator.go
index 93701e799..020d08089 100644
--- a/hugolib/page__paginator.go
+++ b/hugolib/page__paginator.go
@@ -81,3 +81,7 @@ func (p *pagePaginator) Paginator(options ...interface{}) (*page.Pager, error) {
 
 	return p.current, nil
 }
+
+func (p *pagePaginator) rewind() {
+	p.current = p.current.First()
+}
diff --git a/hugolib/paginator_test.go b/hugolib/paginator_test.go
new file mode 100644
index 000000000..d98ec30e9
--- /dev/null
+++ b/hugolib/paginator_test.go
@@ -0,0 +1,98 @@
+// 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.
+
+package hugolib
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestPaginator(t *testing.T) {
+	configFile := `
+baseURL = "https://example.com/foo/"
+paginate = 3
+paginatepath = "thepage"
+
+[languages.en]
+weight = 1
+contentDir = "content/en"
+
+[languages.nn]
+weight = 2
+contentDir = "content/nn"
+
+`
+	b := newTestSitesBuilder(t).WithConfigFile("toml", configFile)
+	var content []string
+	for i := 0; i < 9; i++ {
+		for _, contentDir := range []string{"content/en", "content/nn"} {
+			content = append(content, fmt.Sprintf(contentDir+"/blog/page%d.md", i), fmt.Sprintf(`---
+title: Page %d
+---
+
+Content.
+`, i))
+		}
+
+	}
+
+	b.WithContent(content...)
+
+	pagTemplate := `
+{{ $pag := $.Paginator }}
+Total: {{ $pag.TotalPages }}
+First: {{ $pag.First.URL }}
+Page Number: {{ $pag.PageNumber }}
+URL: {{ $pag.URL }}
+{{ with $pag.Next }}Next: {{ .URL }}{{ end }}
+{{ with $pag.Prev }}Prev: {{ .URL }}{{ end }}
+{{ range $i, $e := $pag.Pagers }}
+{{ printf "%d: %d/%d  %t" $i $pag.PageNumber .PageNumber (eq . $pag) -}}
+{{ end }}
+`
+
+	b.WithTemplatesAdded("index.html", pagTemplate)
+	b.WithTemplatesAdded("index.xml", pagTemplate)
+
+	b.Build(BuildCfg{})
+
+	b.AssertFileContent("public/index.html",
+		"Page Number: 1",
+		"0: 1/1  true")
+
+	b.AssertFileContent("public/thepage/2/index.html",
+		"Total: 3",
+		"Page Number: 2",
+		"URL: /foo/thepage/2/",
+		"Next: /foo/thepage/3/",
+		"Prev: /foo/",
+		"1: 2/2  true",
+	)
+
+	b.AssertFileContent("public/index.xml",
+		"Page Number: 1",
+		"0: 1/1  true")
+	b.AssertFileContent("public/thepage/2/index.xml",
+		"Page Number: 2",
+		"1: 2/2  true")
+
+	b.AssertFileContent("public/nn/index.html",
+		"Page Number: 1",
+		"0: 1/1  true")
+
+	b.AssertFileContent("public/nn/index.xml",
+		"Page Number: 1",
+		"0: 1/1  true")
+
+}
diff --git a/hugolib/site_render.go b/hugolib/site_render.go
index 1d8b14b0a..760704053 100644
--- a/hugolib/site_render.go
+++ b/hugolib/site_render.go
@@ -172,7 +172,11 @@ func (s *Site) renderPaginator(p *pageState, layouts []string) error {
 	d.Type = f
 
 	// Rewind
-	p.paginator.current = p.paginator.current.First()
+	p.paginator.rewind()
+	defer func() {
+		// Prepare for any re-rendering in server mode.
+		p.paginator.rewind()
+	}()
 
 	// Write alias for page 1
 	d.Addends = fmt.Sprintf("/%s/%d", paginatePath, 1)
diff --git a/tpl/tplimpl/embedded/templates.autogen.go b/tpl/tplimpl/embedded/templates.autogen.go
index d55e5b307..89078350e 100644
--- a/tpl/tplimpl/embedded/templates.autogen.go
+++ b/tpl/tplimpl/embedded/templates.autogen.go
@@ -239,21 +239,22 @@ if (!doNotTrack) {
     <li class="page-item{{ if not $pag.HasPrev }} disabled{{ end }}">
     <a href="{{ if $pag.HasPrev }}{{ $pag.Prev.URL }}{{ end }}" class="page-link" aria-label="Previous"><span aria-hidden="true">&laquo;</span></a>
     </li>
-    {{ $.Scratch.Set "__paginator.ellipsed" false }}
+    {{ $ellipsed := false }}
+    {{ $shouldEllipse := false }}
     {{ range $pag.Pagers }}
     {{ $right := sub .TotalPages .PageNumber }}
     {{ $showNumber := or (le .PageNumber 3) (eq $right 0) }}
     {{ $showNumber := or $showNumber (and (gt .PageNumber (sub $pag.PageNumber 2)) (lt .PageNumber (add $pag.PageNumber 2)))  }}
     {{ if $showNumber }}
-        {{ $.Scratch.Set "__paginator.ellipsed" false }}
-        {{ $.Scratch.Set "__paginator.shouldEllipse" false }}
+        {{ $ellipsed = false }}
+        {{ $shouldEllipse = false }}
     {{ else }}
-        {{ $.Scratch.Set "__paginator.shouldEllipse" (not ($.Scratch.Get "__paginator.ellipsed") ) }}
-        {{ $.Scratch.Set "__paginator.ellipsed" true }}
+        {{ $shouldEllipse = not $ellipsed }}
+        {{ $ellipsed = true }}
     {{ end }}
     {{ if $showNumber }}
     <li class="page-item{{ if eq . $pag }} active{{ end }}"><a class="page-link" href="{{ .URL }}">{{ .PageNumber }}</a></li>
-    {{ else if ($.Scratch.Get "__paginator.shouldEllipse") }}
+    {{ else if $shouldEllipse }}
     <li class="page-item disabled"><span aria-hidden="true">&nbsp;&hellip;&nbsp;</span></li>
     {{ end }}
     {{ end }}
diff --git a/tpl/tplimpl/embedded/templates/pagination.html b/tpl/tplimpl/embedded/templates/pagination.html
index 7995061d9..1c2d2d82f 100644
--- a/tpl/tplimpl/embedded/templates/pagination.html
+++ b/tpl/tplimpl/embedded/templates/pagination.html
@@ -9,21 +9,22 @@
     <li class="page-item{{ if not $pag.HasPrev }} disabled{{ end }}">
     <a href="{{ if $pag.HasPrev }}{{ $pag.Prev.URL }}{{ end }}" class="page-link" aria-label="Previous"><span aria-hidden="true">&laquo;</span></a>
     </li>
-    {{ $.Scratch.Set "__paginator.ellipsed" false }}
+    {{ $ellipsed := false }}
+    {{ $shouldEllipse := false }}
     {{ range $pag.Pagers }}
     {{ $right := sub .TotalPages .PageNumber }}
     {{ $showNumber := or (le .PageNumber 3) (eq $right 0) }}
     {{ $showNumber := or $showNumber (and (gt .PageNumber (sub $pag.PageNumber 2)) (lt .PageNumber (add $pag.PageNumber 2)))  }}
     {{ if $showNumber }}
-        {{ $.Scratch.Set "__paginator.ellipsed" false }}
-        {{ $.Scratch.Set "__paginator.shouldEllipse" false }}
+        {{ $ellipsed = false }}
+        {{ $shouldEllipse = false }}
     {{ else }}
-        {{ $.Scratch.Set "__paginator.shouldEllipse" (not ($.Scratch.Get "__paginator.ellipsed") ) }}
-        {{ $.Scratch.Set "__paginator.ellipsed" true }}
+        {{ $shouldEllipse = not $ellipsed }}
+        {{ $ellipsed = true }}
     {{ end }}
     {{ if $showNumber }}
     <li class="page-item{{ if eq . $pag }} active{{ end }}"><a class="page-link" href="{{ .URL }}">{{ .PageNumber }}</a></li>
-    {{ else if ($.Scratch.Get "__paginator.shouldEllipse") }}
+    {{ else if $shouldEllipse }}
     <li class="page-item disabled"><span aria-hidden="true">&nbsp;&hellip;&nbsp;</span></li>
     {{ end }}
     {{ end }}