1 files changed, 82 insertions, 0 deletions
diff --git a/test/fixedbugs/issue13162.go b/test/fixedbugs/issue13162.go
new file mode 100644
index 0000000..f8b3150
--- /dev/null
+++ b/test/fixedbugs/issue13162.go
@@ -0,0 +1,82 @@
+// run
+
+// Copyright 2016 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.
+
+// Ensure that range loops over a string have the requisite side-effects.
+
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func check(n int) {
+	var i int
+	var r rune
+
+	b := make([]byte, n)
+	for i = range b {
+		b[i] = byte(i + 1)
+	}
+	s := string(b)
+
+	// When n == 0, i is untouched by the range loop.
+	// Picking an initial value of -1 for i makes the
+	// "want" calculation below correct in all cases.
+	i = -1
+	for i = range s {
+		b[i] = s[i]
+	}
+	if want := n - 1; i != want {
+		fmt.Printf("index after range with side-effect = %d want %d\n", i, want)
+		os.Exit(1)
+	}
+
+	i = -1
+	r = '\x00'
+	for i, r = range s {
+		b[i] = byte(r)
+	}
+	if want := n - 1; i != want {
+		fmt.Printf("index after range with side-effect = %d want %d\n", i, want)
+		os.Exit(1)
+	}
+	if want := rune(n); r != want {
+		fmt.Printf("rune after range with side-effect = %q want %q\n", r, want)
+		os.Exit(1)
+	}
+
+	i = -1
+	// i is shadowed here, so its value should be unchanged.
+	for i := range s {
+		b[i] = s[i]
+	}
+	if want := -1; i != want {
+		fmt.Printf("index after range without side-effect = %d want %d\n", i, want)
+		os.Exit(1)
+	}
+
+	i = -1
+	r = -1
+	// i and r are shadowed here, so their values should be unchanged.
+	for i, r := range s {
+		b[i] = byte(r)
+	}
+	if want := -1; i != want {
+		fmt.Printf("index after range without side-effect = %d want %d\n", i, want)
+		os.Exit(1)
+	}
+	if want := rune(-1); r != want {
+		fmt.Printf("rune after range without side-effect = %q want %q\n", r, want)
+		os.Exit(1)
+	}
+}
+
+func main() {
+	check(0)
+	check(1)
+	check(15)
+}