take two for 4919

4919.patch

From 0376e727e813a76ddd034d23bfe6b9ee4fece452 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Mon, 6 Apr 2020 00:02:13 +0200
Subject: [PATCH] http: fix EAGAIN handling when sending huge request

---
 lib/http.c     | 2 +-
 lib/transfer.c | 6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/http.c b/lib/http.c
index bff3adc17..d59a47af8 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -1287,11 +1287,11 @@ CURLcode Curl_add_buffer_send(Curl_send_buffer **inp,
         http->postdata = ptr;
         http->postsize = (curl_off_t)size;
 
         http->send_buffer = in;
         http->sending = HTTPSEND_REQUEST;
-
+        DEBUGF(infof(data, "Couldn't send the whole request at once\n"));
         return CURLE_OK;
       }
       http->sending = HTTPSEND_BODY;
       /* the full buffer was sent, clean up and return */
     }
diff --git a/lib/transfer.c b/lib/transfer.c
index 27c984f8f..3b387902e 100644
--- a/lib/transfer.c
+++ b/lib/transfer.c
@@ -1835,14 +1835,17 @@ Curl_setup_transfer(
                                the same we read from. -1 disables */
   )
 {
   struct SingleRequest *k = &data->req;
   struct connectdata *conn = data->conn;
+  struct HTTP *http = data->req.protop;
   DEBUGASSERT(conn != NULL);
   DEBUGASSERT((sockindex <= 1) && (sockindex >= -1));
 
-  if(conn->bits.multiplex || conn->httpversion == 20) {
+  if(conn->bits.multiplex || conn->httpversion == 20 ||
+     ((conn->handler->protocol&PROTO_FAMILY_HTTP) &&
+      http->sending == HTTPSEND_REQUEST)) {
     /* when multiplexing, the read/write sockets need to be the same! */
     conn->sockfd = sockindex == -1 ?
       ((writesockindex == -1 ? CURL_SOCKET_BAD : conn->sock[writesockindex])) :
       conn->sock[sockindex];
     conn->writesockfd = conn->sockfd;
@@ -1871,11 +1874,10 @@ Curl_setup_transfer(
 
     if(sockindex != -1)
       k->keepon |= KEEP_RECV;
 
     if(writesockindex != -1) {
-      struct HTTP *http = data->req.protop;
       /* HTTP 1.1 magic:
 
          Even if we require a 100-return code before uploading data, we might
          need to write data before that since the REQUEST may not have been
          finished sent off just yet.
-- 
2.21.0