cmd/gc: allow append and complex builtins to accept 2-result call expression as first argument.
Fixes #5793.
LGTM=rsc
R=rsc, adonovan, dave
CC=golang-codereviews
https://golang.org/cl/13367051
diff --git a/test/fixedbugs/issue5793.go b/test/fixedbugs/issue5793.go
new file mode 100644
index 0000000..f5a9965
--- /dev/null
+++ b/test/fixedbugs/issue5793.go
@@ -0,0 +1,36 @@
+// run
+
+// Copyright 2013 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 5793: calling 2-arg builtin with multiple-result f() call expression gives
+// spurious error.
+
+package main
+
+func complexArgs() (float64, float64) {
+ return 5, 7
+}
+
+func appendArgs() ([]string, string) {
+ return []string{"foo"}, "bar"
+}
+
+func appendMultiArgs() ([]byte, byte, byte) {
+ return []byte{'a', 'b'}, '1', '2'
+}
+
+func main() {
+ if c := complex(complexArgs()); c != 5+7i {
+ panic(c)
+ }
+
+ if s := append(appendArgs()); len(s) != 2 || s[0] != "foo" || s[1] != "bar" {
+ panic(s)
+ }
+
+ if b := append(appendMultiArgs()); len(b) != 4 || b[0] != 'a' || b[1] != 'b' || b[2] != '1' || b[3] != '2' {
+ panic(b)
+ }
+}
