From 6e2925d8421cb3bee8ee8ad95c4737f35baf91cf Mon Sep 17 00:00:00 2001
From: Melanie Seltzer <melleh11@gmail.com>
Date: Thu, 3 Oct 2019 23:18:26 -0700
Subject: [PATCH] Dedupe meta tag in favor of custom tag defined in _app

---
 packages/next/next-server/lib/head.tsx | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/packages/next/next-server/lib/head.tsx b/packages/next/next-server/lib/head.tsx
index bd5e6e7e78da1..bee5242e0c3b1 100644
--- a/packages/next/next-server/lib/head.tsx
+++ b/packages/next/next-server/lib/head.tsx
@@ -72,6 +72,12 @@ function unique() {
       keys.add(h.key)
       return true
     }
+
+    // If custom meta tag has been added the key will be prepended with `.$`, we can
+    // check for this and dedupe in favor of the custom one, so the default
+    // is not rendered as well
+    if (keys.has(`.$${h.key}`)) return false
+
     switch (h.type) {
       case 'title':
       case 'base':