reflect: set dir when creating a channel via ChanOf

Fixes #9135

Change-Id: I4d0e4eb52a3d64262f107eb7eae4096a6e47ac08
Reviewed-on: https://go-review.googlesource.com/2238Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/reflect/all_test.go

@@ -3487,6 +3487,26 @@ func TestChanOf(t *testing.T) {
 	checkSameType(t, Zero(ChanOf(BothDir, TypeOf(T1(1)))).Interface(), (chan T1)(nil))
 }
 
+func TestChanOfDir(t *testing.T) {
+	// check construction and use of type not in binary
+	type T string
+	crt := ChanOf(RecvDir, TypeOf(T("")))
+	cst := ChanOf(SendDir, TypeOf(T("")))
+
+	// check that type already in binary is found
+	type T1 int
+	checkSameType(t, Zero(ChanOf(RecvDir, TypeOf(T1(1)))).Interface(), (<-chan T1)(nil))
+	checkSameType(t, Zero(ChanOf(SendDir, TypeOf(T1(1)))).Interface(), (chan<- T1)(nil))
+
+	// check String form of ChanDir
+	if crt.ChanDir().String() != "<-chan" {
+		t.Errorf("chan dir: have %q, want %q", crt.ChanDir().String(), "<-chan")
+	}
+	if cst.ChanDir().String() != "chan<-" {
+		t.Errorf("chan dir: have %q, want %q", cst.ChanDir().String(), "chan<-")
+	}
+}
+
 func TestChanOfGC(t *testing.T) {
 	done := make(chan bool, 1)
 	go func() {

src/reflect/type.go

@@ -1425,6 +1425,7 @@ func ChanOf(dir ChanDir, t Type) Type {
 	prototype := *(**chanType)(unsafe.Pointer(&ichan))
 	ch := new(chanType)
 	*ch = *prototype
+	ch.dir = uintptr(dir)
 	ch.string = &s
 	ch.hash = fnv1(typ.hash, 'c', byte(dir))
 	ch.elem = typ