gddo-server: do not redirect /fonts/* requests

Change-Id: Ib1b089640af5e70defd7625515ee11d961c132da
Reviewed-on: https://go-review.googlesource.com/c/gddo/+/287212
Trust: Julie Qiu <julie@golang.org>
Run-TryBot: Julie Qiu <julie@golang.org>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
diff --git a/gddo-server/pkgsite.go b/gddo-server/pkgsite.go
index 2bf2646..bf683a0 100644
--- a/gddo-server/pkgsite.go
+++ b/gddo-server/pkgsite.go
@@ -103,11 +103,14 @@
 // pkg.go.dev.
 var doNotTeeExtsToPkgGoDev = map[string]bool{
 	".css":  true,
+	".eot":  true,
 	".html": true,
-	".js":   true,
-	".txt":  true,
-	".xml":  true,
 	".ico":  true,
+	".js":   true,
+	".ttf":  true,
+	".txt":  true,
+	".woff": true,
+	".xml":  true,
 }
 
 // shouldTeeRequest reports whether a request should be teed to pkg.go.dev.
@@ -116,6 +119,9 @@
 	if strings.HasPrefix(u, "/_ah/") {
 		return false
 	}
+	if strings.HasPrefix(u, "/fonts/") {
+		return false
+	}
 	ext := filepath.Ext(u)
 	if doNotTeeExtsToPkgGoDev[ext] {
 		return false
@@ -291,7 +297,7 @@
 }
 
 func isStdlibURLPath(path string) bool {
-	if strings.HasPrefix(path, "/-/") {
+	if strings.HasPrefix(path, "/-/") || strings.HasPrefix(path, "/fonts/") {
 		return false
 	}
 	path = strings.TrimPrefix(path, "/")