From 3d80b4e93b0f7e857d6e9681d8d6a429750ecf80 Mon Sep 17 00:00:00 2001
From: Tyler Bui-Palsulich <26876514+tbpg@users.noreply.github.com>
Date: Wed, 3 Mar 2021 11:40:05 -0500
Subject: [PATCH] fix(internal/godocfx): prevent index out of bounds when pkg
 == mod (#3768)

---
 internal/godocfx/parse.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/internal/godocfx/parse.go b/internal/godocfx/parse.go
index 68ce87ef924..cabe8ceb834 100644
--- a/internal/godocfx/parse.go
+++ b/internal/godocfx/parse.go
@@ -461,7 +461,10 @@ func (l *linker) toURL(pkg, name string) string {
 		return fmt.Sprintf("#%s", name)
 	}
 	if mod, ok := l.sameDomainModules[pkg]; ok {
-		pkgRemainder := pkg[len(mod.Path)+1:] // +1 to skip slash.
+		pkgRemainder := ""
+		if pkg != mod.Path {
+			pkgRemainder = pkg[len(mod.Path)+1:] // +1 to skip slash.
+		}
 		// Note: we always link to latest. One day, we'll link to mod.Version.
 		baseURL := fmt.Sprintf("/go/docs/reference/%v/latest/%v", mod.Path, pkgRemainder)
 		if anchor := l.idToAnchor[pkg][name]; anchor != "" {