[release-branch.go1.4] cmd/gc: don't unpack struct arguments to append

Fixes #9634.

Change-Id: I7b18f26c2fb812978fc7adc5bfd39ebfffe48701
Reviewed-on: https://go-review.googlesource.com/3080
Reviewed-by: Minux Ma <minux@golang.org>
(cherry picked from commit f5b8813e93f3d61556ecc0ba112478fa319e4e30)
Reviewed-on: https://go-review.googlesource.com/5000
Run-TryBot: Andrew Gerrand <adg@golang.org>

diff --git a/src/cmd/gc/typecheck.c b/src/cmd/gc/typecheck.c
index 714c662681e92b58adbd9249b6641ea42c5ca11e..ce12f150a59f5f87a9d69831040e3413e0cb92fb 100644 (file)
--- a/src/cmd/gc/typecheck.c
+++ b/src/cmd/gc/typecheck.c
@@ -1335,7 +1335,7 @@ reswitch:
                        goto error;
 
                // Unpack multiple-return result before type-checking.
-               if(istype(t, TSTRUCT)) {
+               if(istype(t, TSTRUCT) && t->funarg) {
                        t = t->type;
                        if(istype(t, TFIELD))
                                t = t->type;

diff --git a/test/fixedbugs/issue9634.go b/test/fixedbugs/issue9634.go
new file mode 100644 (file)
index 0000000..2d5aae4
--- /dev/null
+++ b/test/fixedbugs/issue9634.go
@@ -0,0 +1,18 @@
+// errorcheck
+
+// Copyright 2015 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.
+
+// Issue 9634: Structs are incorrectly unpacked when passed as an argument
+// to append.
+
+package main
+
+func main() {
+       s := struct{
+               t []int
+               u int
+       }{}
+       _ = append(s, 0) // ERROR "must be a slice|must be slice"
+}