Fix segfault

src/core/surface/call.c

@@ -146,10 +146,10 @@ struct grpc_call {
   /* Active ioreqs.
      request_set and request_data contain one element per active ioreq
      operation.
-     
+
      request_set[op] is an integer specifying a set of operations to which
      the request belongs:
-       - if it is < GRPC_IOREQ_OP_COUNT, then this operation is pending 
+       - if it is < GRPC_IOREQ_OP_COUNT, then this operation is pending
          completion, and the integer represents to which group of operations
          the ioreq belongs. Each group is represented by one master, and the
          integer in request_set is an index into masters to find the master
@@ -158,7 +158,7 @@ struct grpc_call {
          started
        - finally, if request_set[op] is REQSET_DONE, then the operation is
          complete and unavailable to be started again
-     
+
      request_data[op] is the request data as supplied by the initiator of
      a request, and is valid iff request_set[op] <= GRPC_IOREQ_OP_COUNT.
      The set fields are as per the request type specified by op.
@@ -200,12 +200,12 @@ struct grpc_call {
   /* Call refcount - to keep the call alive during asynchronous operations */
   gpr_refcount internal_refcount;
 
-  /* Data that the legacy api needs to track. To be deleted at some point 
+  /* Data that the legacy api needs to track. To be deleted at some point
      soon */
   legacy_state *legacy_state;
 };
 
-#define CALL_STACK_FROM_CALL(call) ((grpc_call_stack *)((call) + 1))
+#define CALL_STACK_FROM_CALL(call) ((grpc_call_stack *)((call)+1))
 #define CALL_FROM_CALL_STACK(call_stack) (((grpc_call *)(call_stack)) - 1)
 #define CALL_ELEM_FROM_CALL(call, idx) \
   grpc_call_stack_element(CALL_STACK_FROM_CALL(call), idx)
@@ -335,7 +335,9 @@ static void unlock(grpc_call *call) {
   completed_request completed_requests[GRPC_IOREQ_OP_COUNT];
   int num_completed_requests = call->num_completed_requests;
   int need_more_data =
-      call->need_more_data && !is_op_live(call, GRPC_IOREQ_SEND_INITIAL_METADATA);
+      call->need_more_data &&
+      !is_op_live(call, GRPC_IOREQ_SEND_INITIAL_METADATA) &&
+      call->request_set[GRPC_IOREQ_SEND_INITIAL_METADATA] != REQSET_EMPTY;
   int i;
 
   if (need_more_data) {
@@ -854,7 +856,7 @@ static gpr_uint32 decode_status(grpc_mdelem *md) {
   gpr_uint32 status;
   void *user_data = grpc_mdelem_get_user_data(md, destroy_status);
   if (user_data) {
-    status = ((gpr_uint32)(gpr_intptr)user_data) - STATUS_OFFSET;
+    status = ((gpr_uint32)(gpr_intptr) user_data) - STATUS_OFFSET;
   } else {
     if (!gpr_parse_bytes_to_uint32(grpc_mdstr_as_c_string(md->value),
                                    GPR_SLICE_LENGTH(md->value->slice),