3 files changed, 149 insertions, 0 deletions
diff --git a/src/cmd/gofmt/gofmt_test.go b/src/cmd/gofmt/gofmt_test.go
index 303c4f1e1..4b2805009 100644
--- a/src/cmd/gofmt/gofmt_test.go
+++ b/src/cmd/gofmt/gofmt_test.go
@@ -77,6 +77,7 @@ var tests = []struct {
 	{"testdata/rewrite1.input", "-r=Foo->Bar"},
 	{"testdata/rewrite2.input", "-r=int->bool"},
 	{"testdata/rewrite3.input", "-r=x->x"},
+	{"testdata/rewrite4.input", "-r=(x)->x"},
 	{"testdata/stdin*.input", "-stdin"},
 	{"testdata/comments.input", ""},
 	{"testdata/import.input", ""},
diff --git a/src/cmd/gofmt/testdata/rewrite4.golden b/src/cmd/gofmt/testdata/rewrite4.golden
new file mode 100644
index 000000000..8dfc81a07
--- /dev/null
+++ b/src/cmd/gofmt/testdata/rewrite4.golden
@@ -0,0 +1,74 @@
+// Copyright 2012 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.
+
+// Rewriting of parenthesized expressions (x) -> x
+// must not drop parentheses if that would lead to
+// wrong association of the operands.
+// Was issue 1847.
+
+package main
+
+// From example 1 of issue 1847.
+func _() {
+	var t = (&T{1000}).Id()
+}
+
+// From example 2 of issue 1847.
+func _() {
+	fmt.Println((*xpp).a)
+}
+
+// Some more test cases.
+func _() {
+	_ = (-x).f
+	_ = (*x).f
+	_ = (&x).f
+	_ = (!x).f
+	_ = -x.f
+	_ = *x.f
+	_ = &x.f
+	_ = !x.f
+	(-x).f()
+	(*x).f()
+	(&x).f()
+	(!x).f()
+	_ = -x.f()
+	_ = *x.f()
+	_ = &x.f()
+	_ = !x.f()
+
+	_ = (-x).f
+	_ = (*x).f
+	_ = (&x).f
+	_ = (!x).f
+	_ = -x.f
+	_ = *x.f
+	_ = &x.f
+	_ = !x.f
+	(-x).f()
+	(*x).f()
+	(&x).f()
+	(!x).f()
+	_ = -x.f()
+	_ = *x.f()
+	_ = &x.f()
+	_ = !x.f()
+
+	_ = -x.f
+	_ = *x.f
+	_ = &x.f
+	_ = !x.f
+	_ = -x.f
+	_ = *x.f
+	_ = &x.f
+	_ = !x.f
+	_ = -x.f()
+	_ = *x.f()
+	_ = &x.f()
+	_ = !x.f()
+	_ = -x.f()
+	_ = *x.f()
+	_ = &x.f()
+	_ = !x.f()
+}
diff --git a/src/cmd/gofmt/testdata/rewrite4.input b/src/cmd/gofmt/testdata/rewrite4.input
new file mode 100644
index 000000000..164cc0451
--- /dev/null
+++ b/src/cmd/gofmt/testdata/rewrite4.input
@@ -0,0 +1,74 @@
+// Copyright 2012 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.
+
+// Rewriting of parenthesized expressions (x) -> x
+// must not drop parentheses if that would lead to
+// wrong association of the operands.
+// Was issue 1847.
+
+package main
+
+// From example 1 of issue 1847.
+func _() {
+	var t = (&T{1000}).Id()
+}
+
+// From example 2 of issue 1847.
+func _() {
+       fmt.Println((*xpp).a)
+}
+
+// Some more test cases.
+func _() {
+	_ = (-x).f
+	_ = (*x).f
+	_ = (&x).f
+	_ = (!x).f
+	_ = (-x.f)
+	_ = (*x.f)
+	_ = (&x.f)
+	_ = (!x.f)
+	(-x).f()
+	(*x).f()
+	(&x).f()
+	(!x).f()
+	_ = (-x.f())
+	_ = (*x.f())
+	_ = (&x.f())
+	_ = (!x.f())
+
+	_ = ((-x)).f
+	_ = ((*x)).f
+	_ = ((&x)).f
+	_ = ((!x)).f
+	_ = ((-x.f))
+	_ = ((*x.f))
+	_ = ((&x.f))
+	_ = ((!x.f))
+	((-x)).f()
+	((*x)).f()
+	((&x)).f()
+	((!x)).f()
+	_ = ((-x.f()))
+	_ = ((*x.f()))
+	_ = ((&x.f()))
+	_ = ((!x.f()))
+
+	_ = -(x).f
+	_ = *(x).f
+	_ = &(x).f
+	_ = !(x).f
+	_ = -x.f
+	_ = *x.f
+	_ = &x.f
+	_ = !x.f
+	_ = -(x).f()
+	_ = *(x).f()
+	_ = &(x).f()
+	_ = !(x).f()
+	_ = -x.f()
+	_ = *x.f()
+	_ = &x.f()
+	_ = !x.f()
+}