From: Daniel Stenberg <daniel@haxx.se>
Date: Fri, 19 Sep 2025 11:23:14 +0000 (+0200)
Subject: cf_socket_recv: don't count reading zero bytes as first byte
X-Git-Tag: rc-8_17_0-1~342
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=df60e8fe701e189e7629fd08b61950a0fb1b697a;p=thirdparty%2Fcurl.git

cf_socket_recv: don't count reading zero bytes as first byte

Reported in Joshua's sarif data

Closes #18615
---

diff --git a/lib/cf-socket.c b/lib/cf-socket.c
index f449ca36ca..308325ccdc 100644
--- a/lib/cf-socket.c
+++ b/lib/cf-socket.c
@@ -1578,7 +1578,7 @@ static CURLcode cf_socket_recv(struct Curl_cfilter *cf, struct Curl_easy *data,
     *pnread = (size_t)nread;
 
   CURL_TRC_CF(data, cf, "recv(len=%zu) -> %d, %zu", len, result, *pnread);
-  if(!result && !ctx->got_first_byte) {
+  if(!result && !ctx->got_first_byte && nread) {
     ctx->first_byte_at = curlx_now();
     ctx->got_first_byte = TRUE;
   }