nghttpx: Process buffered data first without reading additional data

src/shrpx_client_handler.cc

@@ -97,9 +97,13 @@ int ClientHandler::read_clear() {
   ev_timer_again(loop_, &rt_);
 
   for (;;) {
+    // we should process buffered data first before we read EOF.
     if (rb_.rleft() && on_read() != 0) {
       return -1;
     }
+    if (rb_.rleft()) {
+      return 0;
+    }
     rb_.reset();
     struct iovec iov[2];
     auto iovcnt = rb_.wiovec(iov);
@@ -222,10 +226,13 @@ int ClientHandler::read_tls() {
   ev_timer_again(loop_, &rt_);
 
   for (;;) {
+    // we should process buffered data first before we read EOF.
     if (rb_.rleft() && on_read() != 0) {
       return -1;
     }
-
+    if (rb_.rleft()) {
+      return 0;
+    }
     rb_.reset();
     struct iovec iov[2];
     auto iovcnt = rb_.wiovec(iov);

src/shrpx_http2_session.cc

@@ -1537,9 +1537,13 @@ int Http2Session::read_clear() {
   ev_timer_again(loop_, &rt_);
 
   for (;;) {
+    // we should process buffered data first before we read EOF.
     if (rb_.rleft() && on_read() != 0) {
       return -1;
     }
+    if (rb_.rleft()) {
+      return 0;
+    }
     rb_.reset();
     struct iovec iov[2];
     auto iovcnt = rb_.wiovec(iov);
@@ -1661,10 +1665,13 @@ int Http2Session::read_tls() {
   ev_timer_again(loop_, &rt_);
 
   for (;;) {
+    // we should process buffered data first before we read EOF.
     if (rb_.rleft() && on_read() != 0) {
       return -1;
     }
-
+    if (rb_.rleft()) {
+      return 0;
+    }
     rb_.reset();
     struct iovec iov[2];
     auto iovcnt = rb_.wiovec(iov);