hugolib: Fix ref/relref issue with duplicate base filenames

This commit also makes that function 80x faster.

Fixes #2507

hugolib/page_collections.go

@@ -61,8 +61,9 @@ func (c *PageCollections) refreshPageCaches() {
 				// shortcodes. If the user says "sect/doc1.en.md", he/she knows
 				// what he/she is looking for.
 				for _, p := range c.AllRegularPages {
-					// TODO(bep) section
 					cache[filepath.ToSlash(p.Source.Path())] = p
+					// Ref/Relref supports this potentially ambiguous lookup.
+					cache[p.Source.LogicalName()] = p
 				}
 			default:
 				for _, p := range c.indexPages {

hugolib/page_collections_test.go

@@ -110,6 +110,9 @@ func TestGetPage(t *testing.T) {
 		}
 	}
 
+	content := fmt.Sprintf(pageCollectionsPageTemplate, "UniqueBase")
+	writeSource(t, fs, filepath.Join("content", "sect3", "unique.md"), content)
+
 	s := buildSingleSite(t, deps.DepsCfg{Fs: fs, Cfg: cfg}, BuildCfg{SkipRender: true})
 
 	tests := []struct {
@@ -122,7 +125,8 @@ func TestGetPage(t *testing.T) {
 		{KindPage, []string{"sect3", "page1.md"}, "Title3_1"},
 		{KindPage, []string{"sect4/page2.md"}, "Title4_2"},
 		{KindPage, []string{filepath.FromSlash("sect5/page3.md")}, "Title5_3"},
-		// TODO(bep) section maybe support sect5/page2, aka relref.
+		// Ref/Relref supports this potentially ambiguous lookup.
+		{KindPage, []string{"unique.md"}, "UniqueBase"},
 	}
 
 	for i, test := range tests {

hugolib/site.go

@@ -427,13 +427,7 @@ func (s *SiteInfo) refLink(ref string, page *Page, relative bool, outputFormat s
 	var link string
 
 	if refURL.Path != "" {
-		for _, page := range s.AllRegularPages {
-			refPath := filepath.FromSlash(refURL.Path)
-			if page.Source.Path() == refPath || page.Source.LogicalName() == refPath {
-				target = page
-				break
-			}
-		}
+		target := s.getPage(KindPage, refURL.Path)
 
 		if target == nil {
 			return "", fmt.Errorf("No page found with path or logical name \"%s\".\n", refURL.Path)

hugolib/site_test.go

@@ -907,6 +907,7 @@ func findPage(site *Site, f string) *Page {
 
 func setupLinkingMockSite(t *testing.T) *Site {
 	sources := []source.ByteSource{
+		{Name: filepath.FromSlash("level2/unique.md"), Content: []byte("")},
 		{Name: filepath.FromSlash("index.md"), Content: []byte("")},
 		{Name: filepath.FromSlash("rootfile.md"), Content: []byte("")},
 		{Name: filepath.FromSlash("root-image.png"), Content: []byte("")},
@@ -957,15 +958,11 @@ func TestRefLinking(t *testing.T) {
 		relative     bool
 		expected     string
 	}{
-		// Note: There are no magic in the index.md name. This was fixed in Hugo 0.20.
-		// Before that, index.md would wrongly resolve to "/".
-		// See #3396 -- there is an ambiguity in the examples below, even if they do work.
-		// TODO(bep) better test cases
-		{"index.md", "", true, "/"},
-		{"common.md", "", true, "/level2/common/"},
+		{"unique.md", "", true, "/level2/unique/"},
+		{"level2/common.md", "", true, "/level2/common/"},
 		{"3-root.md", "", true, "/level2/level3/3-root/"},
-		{"index.md", "amp", true, "/amp/"},
-		{"index.md", "amp", false, "http://auth/amp/"},
+		{"level2/level3/index.md", "amp", true, "/amp/level2/level3/"},
+		{"level2/index.md", "amp", false, "http://auth/amp/level2/"},
 	} {
 		if out, err := site.Info.refLink(test.link, currentPage, test.relative, test.outputFormat); err != nil || out != test.expected {
 			t.Errorf("[%d] Expected %s to resolve to (%s), got (%s) - error: %s", i, test.link, test.expected, out, err)