From a9b6594b411ab1e6f221feb65daebaf4ec5ca3f9 Mon Sep 17 00:00:00 2001
From: Will Norris <will@willnorris.com>
Date: Fri, 12 May 2023 19:04:10 -0700
Subject: [PATCH] return early if remote URL returns a 404

---
 imageproxy.go | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/imageproxy.go b/imageproxy.go
index ce671db..699ff0c 100644
--- a/imageproxy.go
+++ b/imageproxy.go
@@ -221,6 +221,12 @@ func (p *Proxy) serveImage(w http.ResponseWriter, r *http.Request) {
 	// close the original resp.Body, even if we wrap it in a NopCloser below
 	defer resp.Body.Close()
 
+	// return early on 404s.  Perhaps handle additional status codes here?
+	if resp.StatusCode == http.StatusNotFound {
+		http.Error(w, "not found", http.StatusNotFound)
+		return
+	}
+
 	cached := resp.Header.Get(httpcache.XFromCache) == "1"
 	if p.Verbose {
 		p.logf("request: %+v (served from cache: %t)", *actualReq, cached)