From 24265b03ac5c6ace73916f3bc3a847abf1c64c33 Mon Sep 17 00:00:00 2001
From: Muxi Yan <mxyan@google.com>
Date: Tue, 6 Nov 2018 11:31:48 -0800
Subject: [PATCH] Clarify cancel before call is started

---
 src/objective-c/GRPCClient/GRPCCall.h | 1 +
 src/objective-c/GRPCClient/GRPCCall.m | 1 +
 2 files changed, 2 insertions(+)

diff --git a/src/objective-c/GRPCClient/GRPCCall.h b/src/objective-c/GRPCClient/GRPCCall.h
index 4f0660d203e..f713262b643 100644
--- a/src/objective-c/GRPCClient/GRPCCall.h
+++ b/src/objective-c/GRPCClient/GRPCCall.h
@@ -245,6 +245,7 @@ extern NSString *const kGRPCTrailersKey;
 
 /**
  * Starts the call. This function should only be called once; additional calls will be discarded.
+ * Invokes after calling cancel: are discarded.
  */
 - (void)start;
 
diff --git a/src/objective-c/GRPCClient/GRPCCall.m b/src/objective-c/GRPCClient/GRPCCall.m
index 9be0554ff98..5ce361300d6 100644
--- a/src/objective-c/GRPCClient/GRPCCall.m
+++ b/src/objective-c/GRPCClient/GRPCCall.m
@@ -209,6 +209,7 @@ const char *kCFStreamVarName = "grpc_cfstream";
 
 - (void)cancel {
   dispatch_async(_dispatchQueue, ^{
+    self->_started = YES;
     if (self->_call) {
       [self->_call cancel];
       self->_call = nil;