From 2af4fd57342e54519787192872638911308c7af4 Mon Sep 17 00:00:00 2001
From: Josh Humphries <2035234+jhump@users.noreply.github.com>
Date: Fri, 12 May 2023 12:07:59 -0400
Subject: [PATCH] fix nil-dereference panic

---
 invoke.go | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/invoke.go b/invoke.go
index b5bae4b..193c285 100644
--- a/invoke.go
+++ b/invoke.go
@@ -264,8 +264,10 @@ func invokeServerStream(ctx context.Context, stub grpcdynamic.Stub, md *desc.Met
 	// Now we can actually invoke the RPC!
 	str, err := stub.InvokeRpcServerStream(ctx, md, req)
 
-	if respHeaders, err := str.Header(); err == nil {
-		handler.OnReceiveHeaders(respHeaders)
+	if str != nil {
+		if respHeaders, err := str.Header(); err == nil {
+			handler.OnReceiveHeaders(respHeaders)
+		}
 	}
 
 	// Download each response message
@@ -288,7 +290,9 @@ func invokeServerStream(ctx context.Context, stub grpcdynamic.Stub, md *desc.Met
 		return fmt.Errorf("grpc call for %q failed: %v", md.GetFullyQualifiedName(), err)
 	}
 
-	handler.OnReceiveTrailers(stat, str.Trailer())
+	if str != nil {
+		handler.OnReceiveTrailers(stat, str.Trailer())
+	}
 
 	return nil
 }