From e75ec8b7e58bf2d31a64f9cdfbbf5637d4f77b57 Mon Sep 17 00:00:00 2001
From: Marc LeBlanc <7050295+marcleblanc2@users.noreply.github.com>
Date: Wed, 16 Sep 2026 18:12:36 -0600
Subject: [PATCH] fix: include deployment id in the webpack cache key

next/font bakes Vercel's ?dpl= skew-protection query into the CSS url()s
at build time, but Next's webpack cache key does not include the
deployment id. With the restored .next/cache the CSS keeps the previous
deployment's id while the HTML preloads use the new one, so every font
downloads twice.
---
 next.config.js | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/next.config.js b/next.config.js
index 2603ca187..72ec05ca2 100644
--- a/next.config.js
+++ b/next.config.js
@@ -32,6 +32,18 @@ const nextConfig = {
 				permanent: false
 			}
 		];
+	},
+	// Vercel's skew protection appends `?dpl=<deployment id>` to asset URLs.
+	// `next/font` bakes that query into the CSS `url()`s at build time, but
+	// Next's webpack cache key ignores the deployment id, so a restored
+	// `.next/cache` re-emits CSS with the previous deployment's id and every
+	// font downloads twice (once per id). Fold the id into the cache key.
+	webpack(config) {
+		const deploymentId = process.env.NEXT_DEPLOYMENT_ID;
+		if (deploymentId && config.cache) {
+			config.cache.version = `${config.cache.version}|${deploymentId}`;
+		}
+		return config;
 	}
 };