From 660200528afbcf203d5cdc53a46fd3be7d2bd35c Mon Sep 17 00:00:00 2001
From: Robert Griesemer <gri@golang.org>
Date: Wed, 7 Jun 2017 13:10:05 -0700
Subject: [PATCH] cmd/compile: don't implicitly dereference pointer to arrays
 for real/imag

Fixes #20602.

Change-Id: Iac1589484dec626c018314e0cea7efce091fd87d
Reviewed-on: https://go-review.googlesource.com/45075
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
---
 src/cmd/compile/internal/gc/typecheck.go |  4 +++-
 test/fixedbugs/issue20602.go             | 14 ++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 test/fixedbugs/issue20602.go

diff --git a/src/cmd/compile/internal/gc/typecheck.go b/src/cmd/compile/internal/gc/typecheck.go
index b02bc659be3..04efcc3d823 100644
--- a/src/cmd/compile/internal/gc/typecheck.go
+++ b/src/cmd/compile/internal/gc/typecheck.go
@@ -1349,7 +1349,9 @@ OpSwitch:
 		}
 		n.Left = typecheck(n.Left, Erv)
 		n.Left = defaultlit(n.Left, nil)
-		n.Left = implicitstar(n.Left)
+		if n.Op == OCAP || n.Op == OLEN {
+			n.Left = implicitstar(n.Left)
+		}
 		l := n.Left
 		t := l.Type
 		if t == nil {
diff --git a/test/fixedbugs/issue20602.go b/test/fixedbugs/issue20602.go
new file mode 100644
index 00000000000..ca4ce095aa2
--- /dev/null
+++ b/test/fixedbugs/issue20602.go
@@ -0,0 +1,14 @@
+// errorcheck
+
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Verify that the correct (not implicitly dereferenced)
+// type is reported in the error message.
+
+package p
+
+var p = &[1]complex128{0}
+var _ = real(p)  // ERROR "type \*\[1\]complex128"
+var _ = imag(p)	 // ERROR "type \*\[1\]complex128"