Let RecvProto return nil for client stream rpc

compiler/go_generator.cc

@@ -286,7 +286,7 @@ void PrintClientMethodImpl(google::protobuf::io::Printer* printer,
         "\t\treturn nil, err\n"
         "\t}\n"
         "\tm := new($Response$)\n"
-        "\tif err := x.ClientStream.RecvProto(m); err != io.EOF {\n"
+        "\tif err := x.ClientStream.RecvProto(m); err != nil {\n"
         "\t\treturn nil, err\n"
         "\t}\n"
         "\treturn m, nil\n"
@@ -618,10 +618,6 @@ string GetServices(const google::protobuf::FileDescriptor* file,
   vars["PackageName"] = BadToUnderscore(package_name);
   printer.Print(vars, "package $PackageName$\n\n");
   printer.Print("import (\n");
-  if (HasClientOnlyStreaming(file)) {
-    printer.Print(
-        "\t\"io\"\n");
-  }
   printer.Print(
       "\t\"google.golang.org/grpc\"\n"
       "\tcontext \"golang.org/x/net/context\"\n"

interop/grpc_testing/test.pb.go

@@ -58,15 +58,11 @@ import proto "github.com/golang/protobuf/proto"
 import math "math"
 
 import (
-	errors "errors"
 	context "golang.org/x/net/context"
 	grpc "google.golang.org/grpc"
-	io "io"
 )
 
 // Reference imports to suppress errors if they are not otherwise used.
-var _ = errors.New
-var _ = io.EOF
 var _ context.Context
 var _ grpc.ClientConn
 
@@ -489,7 +485,7 @@ func (x *testServiceStreamingInputCallClient) CloseAndRecv() (*StreamingInputCal
 		return nil, err
 	}
 	m := new(StreamingInputCallResponse)
-	if err := x.ClientStream.RecvProto(m); err != io.EOF {
+	if err := x.ClientStream.RecvProto(m); err != nil {
 		return nil, err
 	}
 	return m, nil

stream.go

@@ -34,7 +34,7 @@
 package grpc
 
 import (
-	"fmt"
+	"errors"
 	"io"
 	"net"
 
@@ -170,10 +170,18 @@ func (cs *clientStream) RecvProto(m proto.Message) (err error) {
 			return
 		}
 		// Special handling for client streaming rpc.
-		if err = recvProto(cs.p, m); err != io.EOF {
+		err = recvProto(cs.p, m)
-			cs.t.CloseStream(cs.s, err)
+		cs.t.CloseStream(cs.s, err)
-			return fmt.Errorf("grpc: client streaming protocol violation: %v, want <EOF>", err)
+		if err == nil {
+			return toRPCErr(errors.New("grpc: client streaming protocol violation: get <nil>, want <EOF>"))
 		}
+		if err == io.EOF {
+			if cs.s.StatusCode() == codes.OK {
+				return nil
+			}
+			return Errorf(cs.s.StatusCode(), cs.s.StatusDesc())
+		}
+		return toRPCErr(err)
 	}
 	if _, ok := err.(transport.ConnectionError); !ok {
 		cs.t.CloseStream(cs.s, err)

test/grpc_testing/test.pb.go

@@ -58,15 +58,11 @@ import proto "github.com/golang/protobuf/proto"
 import math "math"
 
 import (
-	errors "errors"
 	context "golang.org/x/net/context"
 	grpc "google.golang.org/grpc"
-	io "io"
 )
 
 // Reference imports to suppress errors if they are not otherwise used.
-var _ = errors.New
-var _ = io.EOF
 var _ context.Context
 var _ grpc.ClientConn
 
@@ -489,7 +485,7 @@ func (x *testServiceStreamingInputCallClient) CloseAndRecv() (*StreamingInputCal
 		return nil, err
 	}
 	m := new(StreamingInputCallResponse)
-	if err := x.ClientStream.RecvProto(m); err != io.EOF {
+	if err := x.ClientStream.RecvProto(m); err != nil {
 		return nil, err
 	}
 	return m, nil