fix(gw): ensure dir URLs have trailing slash

This fixes a regression around directory listing and index.html hosting.
Seems that during one of recent refactors code changed and we no longer
check for trailing slash in HTTP request path, but look at content path
instead.

This cleans this up and also ensures dir behavior is the same for
both index.html hosting and dir-index-html (generated listing).

It also adds more tests so we catch any future regressions.


This commit was moved from ipfs/kubo@3182986

gateway/core/corehttp/gateway_handler_unixfs_dir.go

@@ -41,28 +41,30 @@ func (i *gatewayHandler) serveDirectory(ctx context.Context, w http.ResponseWrit
 	}
 	originalUrlPath := requestURI.Path
 
-	// Check if directory has index.html, if so, serveFile
-	idxPath := ipath.Join(contentPath, "index.html")
-	idx, err := i.api.Unixfs().Get(ctx, idxPath)
-	switch err.(type) {
-	case nil:
-		cpath := contentPath.String()
-		dirwithoutslash := cpath[len(cpath)-1] != '/'
+	// Ensure directory paths end with '/'
+	if originalUrlPath[len(originalUrlPath)-1] != '/' {
+		// don't redirect to trailing slash if it's go get
+		// https://github.com/ipfs/kubo/pull/3963
 		goget := r.URL.Query().Get("go-get") == "1"
-		if dirwithoutslash && !goget {
-			// See comment above where originalUrlPath is declared.
+		if !goget {
 			suffix := "/"
+			// preserve query parameters
 			if r.URL.RawQuery != "" {
-				// preserve query parameters
 				suffix = suffix + "?" + r.URL.RawQuery
 			}
-
+			// /ipfs/cid/foo?bar must be redirected to /ipfs/cid/foo/?bar
 			redirectURL := originalUrlPath + suffix
-			logger.Debugw("serving index.html file", "to", redirectURL, "status", http.StatusFound, "path", idxPath)
-			http.Redirect(w, r, redirectURL, http.StatusFound)
+			logger.Debugw("directory location moved permanently", "status", http.StatusMovedPermanently)
+			http.Redirect(w, r, redirectURL, http.StatusMovedPermanently)
 			return
 		}
+	}
 
+	// Check if directory has index.html, if so, serveFile
+	idxPath := ipath.Join(contentPath, "index.html")
+	idx, err := i.api.Unixfs().Get(ctx, idxPath)
+	switch err.(type) {
+	case nil:
 		f, ok := idx.(files.File)
 		if !ok {
 			internalWebError(w, files.ErrNotReader)
@@ -163,7 +165,7 @@ func (i *gatewayHandler) serveDirectory(ctx context.Context, w http.ResponseWrit
 	// add the correct link depending on whether the path ends with a slash
 	default:
 		if strings.HasSuffix(backLink, "/") {
-			backLink += "./.."
+			backLink += ".."
 		} else {
 			backLink += "/.."
 		}

gateway/core/corehttp/gateway_test.go

@@ -380,9 +380,9 @@ func TestIPNSHostnameRedirect(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	// expect 302 redirect to same path, but with trailing slash
-	if res.StatusCode != 302 {
-		t.Errorf("status is %d, expected 302", res.StatusCode)
+	// expect 301 redirect to same path, but with trailing slash
+	if res.StatusCode != 301 {
+		t.Errorf("status is %d, expected 301", res.StatusCode)
 	}
 	hdr := res.Header["Location"]
 	if len(hdr) < 1 {
@@ -403,9 +403,9 @@ func TestIPNSHostnameRedirect(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	// expect 302 redirect to same path, but with prefix and trailing slash
-	if res.StatusCode != 302 {
-		t.Errorf("status is %d, expected 302", res.StatusCode)
+	// expect 301 redirect to same path, but with prefix and trailing slash
+	if res.StatusCode != 301 {
+		t.Errorf("status is %d, expected 301", res.StatusCode)
 	}
 	hdr = res.Header["Location"]
 	if len(hdr) < 1 {
@@ -492,7 +492,7 @@ func TestIPNSHostnameBacklinks(t *testing.T) {
 	if !matchPathOrBreadcrumbs(s, "/ipns/<a href=\"//example.net/\">example.net</a>/<a href=\"//example.net/foo%3F%20%23%3C%27\">foo? #&lt;&#39;</a>") {
 		t.Fatalf("expected a path in directory listing")
 	}
-	if !strings.Contains(s, "<a href=\"/foo%3F%20%23%3C%27/./..\">") {
+	if !strings.Contains(s, "<a href=\"/foo%3F%20%23%3C%27/..\">") {
 		t.Fatalf("expected backlink in directory listing")
 	}
 	if !strings.Contains(s, "<a href=\"/foo%3F%20%23%3C%27/file.txt\">") {
@@ -566,7 +566,7 @@ func TestIPNSHostnameBacklinks(t *testing.T) {
 	if !matchPathOrBreadcrumbs(s, "/ipns/<a href=\"//example.net/\">example.net</a>/<a href=\"//example.net/foo%3F%20%23%3C%27\">foo? #&lt;&#39;</a>/<a href=\"//example.net/foo%3F%20%23%3C%27/bar\">bar</a>") {
 		t.Fatalf("expected a path in directory listing")
 	}
-	if !strings.Contains(s, "<a href=\"/foo%3F%20%23%3C%27/bar/./..\">") {
+	if !strings.Contains(s, "<a href=\"/foo%3F%20%23%3C%27/bar/..\">") {
 		t.Fatalf("expected backlink in directory listing")
 	}
 	if !strings.Contains(s, "<a href=\"/foo%3F%20%23%3C%27/bar/file.txt\">") {