Discard the read buffer on stream error

src/core/transport/chttp2_transport.c

@@ -1019,6 +1019,11 @@ static void check_read_ops(grpc_exec_ctx *exec_ctx,
       stream_global->recv_initial_metadata_ready = NULL;
     }
     if (stream_global->recv_message_ready != NULL) {
+      while (stream_global->seen_error &&
+             (bs = grpc_chttp2_incoming_frame_queue_pop(
+                  &stream_global->incoming_frames)) != NULL) {
+        grpc_byte_stream_destroy(exec_ctx, bs);
+      }
       if (stream_global->incoming_frames.head != NULL) {
         *stream_global->recv_message = grpc_chttp2_incoming_frame_queue_pop(
             &stream_global->incoming_frames);

test/cpp/end2end/async_end2end_test.cc

@@ -989,6 +989,10 @@ class AsyncEnd2endServerTryCancelTest : public AsyncEnd2endTest {
 
     if (server_try_cancel == CANCEL_AFTER_PROCESSING) {
       ServerTryCancel(&srv_ctx);
+
+      // Client reads may fail bacause it is notified that the stream is
+      // cancelled.
+      ignore_cq_result = true;
     }
 
     // Client attemts to read the three messages from the server