1 files changed, 57 insertions, 18 deletions

diff --git a/src/core/ext/filters/http/client/http_client_filter.cc b/src/core/ext/filters/http/client/http_client_filter.cc
index 1678051beb..bf9a01f659 100644
--- a/src/core/ext/filters/http/client/http_client_filter.cc
+++ b/src/core/ext/filters/http/client/http_client_filter.cc
@@ -37,10 +37,31 @@
 #define EXPECTED_CONTENT_TYPE_LENGTH sizeof(EXPECTED_CONTENT_TYPE) - 1
 
 /* default maximum size of payload eligable for GET request */
-static const size_t kMaxPayloadSizeForGet = 2048;
+static constexpr size_t kMaxPayloadSizeForGet = 2048;
+
+static void recv_initial_metadata_ready(void* user_data, grpc_error* error);
+static void recv_trailing_metadata_ready(void* user_data, grpc_error* error);
+static void on_send_message_next_done(void* arg, grpc_error* error);
+static void send_message_on_complete(void* arg, grpc_error* error);
 
 namespace {
 struct call_data {
+  call_data(grpc_call_element* elem, const grpc_call_element_args& args)
+      : call_combiner(args.call_combiner) {
+    GRPC_CLOSURE_INIT(&recv_initial_metadata_ready,
+                      ::recv_initial_metadata_ready, elem,
+                      grpc_schedule_on_exec_ctx);
+    GRPC_CLOSURE_INIT(&recv_trailing_metadata_ready,
+                      ::recv_trailing_metadata_ready, elem,
+                      grpc_schedule_on_exec_ctx);
+    GRPC_CLOSURE_INIT(&on_send_message_next_done, ::on_send_message_next_done,
+                      elem, grpc_schedule_on_exec_ctx);
+    GRPC_CLOSURE_INIT(&send_message_on_complete, ::send_message_on_complete,
+                      elem, grpc_schedule_on_exec_ctx);
+  }
+
+  ~call_data() { GRPC_ERROR_UNREF(recv_initial_metadata_error); }
+
   grpc_call_combiner* call_combiner;
   // State for handling send_initial_metadata ops.
   grpc_linked_mdelem method;
@@ -51,15 +72,18 @@ struct call_data {
   grpc_linked_mdelem user_agent;
   // State for handling recv_initial_metadata ops.
   grpc_metadata_batch* recv_initial_metadata;
-  grpc_closure* original_recv_initial_metadata_ready;
+  grpc_error* recv_initial_metadata_error = GRPC_ERROR_NONE;
+  grpc_closure* original_recv_initial_metadata_ready = nullptr;
   grpc_closure recv_initial_metadata_ready;
   // State for handling recv_trailing_metadata ops.
   grpc_metadata_batch* recv_trailing_metadata;
   grpc_closure* original_recv_trailing_metadata_ready;
   grpc_closure recv_trailing_metadata_ready;
+  grpc_error* recv_trailing_metadata_error = GRPC_ERROR_NONE;
+  bool seen_recv_trailing_metadata_ready = false;
   // State for handling send_message ops.
   grpc_transport_stream_op_batch* send_message_batch;
-  size_t send_message_bytes_read;
+  size_t send_message_bytes_read = 0;
   grpc_core::ManualConstructor<grpc_core::ByteStreamCache> send_message_cache;
   grpc_core::ManualConstructor<grpc_core::ByteStreamCache::CachingByteStream>
       send_message_caching_stream;
@@ -78,7 +102,12 @@ struct channel_data {
 static grpc_error* client_filter_incoming_metadata(grpc_call_element* elem,
                                                    grpc_metadata_batch* b) {
   if (b->idx.named.status != nullptr) {
-    if (grpc_mdelem_eq(b->idx.named.status->md, GRPC_MDELEM_STATUS_200)) {
+    /* If both gRPC status and HTTP status are provided in the response, we
+     * should prefer the gRPC status code, as mentioned in
+     * https://github.com/grpc/grpc/blob/master/doc/http-grpc-status-mapping.md.
+     */
+    if (b->idx.named.grpc_status != nullptr ||
+        grpc_mdelem_eq(b->idx.named.status->md, GRPC_MDELEM_STATUS_200)) {
       grpc_metadata_batch_remove(b, b->idx.named.status);
     } else {
       char* val = grpc_dump_slice(GRPC_MDVALUE(b->idx.named.status->md),
@@ -147,21 +176,39 @@ static void recv_initial_metadata_ready(void* user_data, grpc_error* error) {
   call_data* calld = static_cast<call_data*>(elem->call_data);
   if (error == GRPC_ERROR_NONE) {
     error = client_filter_incoming_metadata(elem, calld->recv_initial_metadata);
+    calld->recv_initial_metadata_error = GRPC_ERROR_REF(error);
   } else {
     GRPC_ERROR_REF(error);
   }
-  GRPC_CLOSURE_RUN(calld->original_recv_initial_metadata_ready, error);
+  grpc_closure* closure = calld->original_recv_initial_metadata_ready;
+  calld->original_recv_initial_metadata_ready = nullptr;
+  if (calld->seen_recv_trailing_metadata_ready) {
+    GRPC_CALL_COMBINER_START(
+        calld->call_combiner, &calld->recv_trailing_metadata_ready,
+        calld->recv_trailing_metadata_error, "continue recv_trailing_metadata");
+  }
+  GRPC_CLOSURE_RUN(closure, error);
 }
 
 static void recv_trailing_metadata_ready(void* user_data, grpc_error* error) {
   grpc_call_element* elem = static_cast<grpc_call_element*>(user_data);
   call_data* calld = static_cast<call_data*>(elem->call_data);
+  if (calld->original_recv_initial_metadata_ready != nullptr) {
+    calld->recv_trailing_metadata_error = GRPC_ERROR_REF(error);
+    calld->seen_recv_trailing_metadata_ready = true;
+    GRPC_CALL_COMBINER_STOP(calld->call_combiner,
+                            "deferring recv_trailing_metadata_ready until "
+                            "after recv_initial_metadata_ready");
+    return;
+  }
   if (error == GRPC_ERROR_NONE) {
     error =
         client_filter_incoming_metadata(elem, calld->recv_trailing_metadata);
   } else {
     GRPC_ERROR_REF(error);
   }
+  error = grpc_error_add_child(
+      error, GRPC_ERROR_REF(calld->recv_initial_metadata_error));
   GRPC_CLOSURE_RUN(calld->original_recv_trailing_metadata_ready, error);
 }
 
@@ -416,25 +463,17 @@ done:
 /* Constructor for call_data */
 static grpc_error* init_call_elem(grpc_call_element* elem,
                                   const grpc_call_element_args* args) {
-  call_data* calld = static_cast<call_data*>(elem->call_data);
-  calld->call_combiner = args->call_combiner;
-  GRPC_CLOSURE_INIT(&calld->recv_initial_metadata_ready,
-                    recv_initial_metadata_ready, elem,
-                    grpc_schedule_on_exec_ctx);
-  GRPC_CLOSURE_INIT(&calld->recv_trailing_metadata_ready,
-                    recv_trailing_metadata_ready, elem,
-                    grpc_schedule_on_exec_ctx);
-  GRPC_CLOSURE_INIT(&calld->send_message_on_complete, send_message_on_complete,
-                    elem, grpc_schedule_on_exec_ctx);
-  GRPC_CLOSURE_INIT(&calld->on_send_message_next_done,
-                    on_send_message_next_done, elem, grpc_schedule_on_exec_ctx);
+  new (elem->call_data) call_data(elem, *args);
   return GRPC_ERROR_NONE;
 }
 
 /* Destructor for call_data */
 static void destroy_call_elem(grpc_call_element* elem,
                               const grpc_call_final_info* final_info,
-                              grpc_closure* ignored) {}
+                              grpc_closure* ignored) {
+  call_data* calld = static_cast<call_data*>(elem->call_data);
+  calld->~call_data();
+}
 
 static grpc_mdelem scheme_from_args(const grpc_channel_args* args) {
   unsigned i;