http2: fix connection reuse when PING comes after last DATA

It turns out the google GFE HTTP/2 servers send a PING frame immediately
after a stream ends and its last DATA has been received by curl. So if
we don't drain that from the socket, it makes the socket readable in
subsequent checks and libcurl then (wrongly) assumes the connection is
dead when trying to reuse the connection.

Reported-by: Joonas Kuorilehto
Discussed in #750

diff --git a/lib/http2.c b/lib/http2.c
index 58274157b61e46db80b2cfa76e309c64fca03cee..fd3cefe4b959b5efc68eaed3a25570705c2f6e34 100644 (file)
--- a/lib/http2.c
+++ b/lib/http2.c
@@ -1149,14 +1149,6 @@ static ssize_t http2_recv(struct connectdata *conn, int sockindex,
 
   (void)sockindex; /* we always do HTTP2 on sockindex 0 */
 
-  /* If stream is closed, return 0 to signal the http routine to close
-     the connection.  We need to handle stream closure here,
-     otherwise, we may be going to read from underlying connection,
-     and gets EAGAIN, and we will get stuck there. */
-  if(stream->memlen == 0 && stream->closed) {
-    return http2_handle_stream_close(conn, data, stream, err);
-  }
-
   /* Nullify here because we call nghttp2_session_send() and they
      might refer to the old buffer. */
   stream->upload_mem = NULL;