QUIC: do not resend empty queue when speeding up handshake.

If client acknowledged an Initial packet with CRYPTO frame and then
sent another Initial packet containing duplicate CRYPTO again, this
could result in resending frames off the empty send queue.

1 files changed, 6 insertions, 1 deletions

diff --git a/src/event/ngx_event_quic.c b/src/event/ngx_event_quic.c
index 0c32be355..f503c48ba 100644
--- a/src/event/ngx_event_quic.c
+++ b/src/event/ngx_event_quic.c
@@ -2846,6 +2846,7 @@ ngx_quic_handle_crypto_frame(ngx_connection_t *c, ngx_quic_header_t *pkt,
 {
     uint64_t                   last;
     ngx_int_t                  rc;
+    ngx_quic_send_ctx_t       *ctx;
     ngx_quic_connection_t     *qc;
     ngx_quic_crypto_frame_t   *f;
     ngx_quic_frames_stream_t  *fs;
@@ -2871,7 +2872,11 @@ ngx_quic_handle_crypto_frame(ngx_connection_t *c, ngx_quic_header_t *pkt,
     /* speeding up handshake completion */
 
     if (pkt->level == ssl_encryption_initial) {
-        ngx_quic_resend_frames(c, ngx_quic_get_send_ctx(qc, pkt->level));
+        ctx = ngx_quic_get_send_ctx(qc, pkt->level);
+
+        if (!ngx_queue_empty(&ctx->sent)) {
+            ngx_quic_resend_frames(c, ctx);
+        }
     }
 
     return NGX_OK;