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-rw-r--r--src/bytes/bytes.go2
-rw-r--r--src/bytes/bytes_test.go47
-rw-r--r--src/strings/strings.go2
-rw-r--r--src/strings/strings_test.go47
4 files changed, 64 insertions, 34 deletions
diff --git a/src/bytes/bytes.go b/src/bytes/bytes.go
index 1871814c6e..23edd5a4be 100644
--- a/src/bytes/bytes.go
+++ b/src/bytes/bytes.go
@@ -583,7 +583,7 @@ func Repeat(b []byte, count int) []byte {
if count < 0 {
panic("bytes: negative Repeat count")
}
- if len(b) >= maxInt/count {
+ if len(b) > maxInt/count {
panic("bytes: Repeat output length overflow")
}
n := len(b) * count
diff --git a/src/bytes/bytes_test.go b/src/bytes/bytes_test.go
index 5e8cf85fd9..200a357bc0 100644
--- a/src/bytes/bytes_test.go
+++ b/src/bytes/bytes_test.go
@@ -1242,33 +1242,48 @@ func repeat(b []byte, count int) (err error) {
// See Issue golang.org/issue/16237
func TestRepeatCatchesOverflow(t *testing.T) {
- tests := [...]struct {
+ type testCase struct {
s string
count int
errStr string
- }{
+ }
+
+ runTestCases := func(prefix string, tests []testCase) {
+ for i, tt := range tests {
+ err := repeat([]byte(tt.s), tt.count)
+ if tt.errStr == "" {
+ if err != nil {
+ t.Errorf("#%d panicked %v", i, err)
+ }
+ continue
+ }
+
+ if err == nil || !strings.Contains(err.Error(), tt.errStr) {
+ t.Errorf("%s#%d got %q want %q", prefix, i, err, tt.errStr)
+ }
+ }
+ }
+
+ const maxInt = int(^uint(0) >> 1)
+
+ runTestCases("", []testCase{
0: {"--", -2147483647, "negative"},
- 1: {"", int(^uint(0) >> 1), ""},
+ 1: {"", maxInt, ""},
2: {"-", 10, ""},
3: {"gopher", 0, ""},
4: {"-", -1, "negative"},
5: {"--", -102, "negative"},
6: {string(make([]byte, 255)), int((^uint(0))/255 + 1), "overflow"},
- }
-
- for i, tt := range tests {
- err := repeat([]byte(tt.s), tt.count)
- if tt.errStr == "" {
- if err != nil {
- t.Errorf("#%d panicked %v", i, err)
- }
- continue
- }
+ })
- if err == nil || !strings.Contains(err.Error(), tt.errStr) {
- t.Errorf("#%d expected %q got %q", i, tt.errStr, err)
- }
+ const is64Bit = 1<<(^uintptr(0)>>63)/2 != 0
+ if !is64Bit {
+ return
}
+
+ runTestCases("64-bit", []testCase{
+ 0: {"-", maxInt, "out of range"},
+ })
}
func runesEqual(a, b []rune) bool {
diff --git a/src/strings/strings.go b/src/strings/strings.go
index 11c558c4c3..d8cc09a24e 100644
--- a/src/strings/strings.go
+++ b/src/strings/strings.go
@@ -570,7 +570,7 @@ func Repeat(s string, count int) string {
if count < 0 {
panic("strings: negative Repeat count")
}
- if len(s) >= maxInt/count {
+ if len(s) > maxInt/count {
panic("strings: Repeat output length overflow")
}
n := len(s) * count
diff --git a/src/strings/strings_test.go b/src/strings/strings_test.go
index ac493c7dcd..4bd3a3c202 100644
--- a/src/strings/strings_test.go
+++ b/src/strings/strings_test.go
@@ -1170,33 +1170,48 @@ func repeat(s string, count int) (err error) {
// See Issue golang.org/issue/16237
func TestRepeatCatchesOverflow(t *testing.T) {
- tests := [...]struct {
+ type testCase struct {
s string
count int
errStr string
- }{
+ }
+
+ runTestCases := func(prefix string, tests []testCase) {
+ for i, tt := range tests {
+ err := repeat(tt.s, tt.count)
+ if tt.errStr == "" {
+ if err != nil {
+ t.Errorf("#%d panicked %v", i, err)
+ }
+ continue
+ }
+
+ if err == nil || !Contains(err.Error(), tt.errStr) {
+ t.Errorf("%s#%d got %q want %q", prefix, i, err, tt.errStr)
+ }
+ }
+ }
+
+ const maxInt = int(^uint(0) >> 1)
+
+ runTestCases("", []testCase{
0: {"--", -2147483647, "negative"},
- 1: {"", int(^uint(0) >> 1), ""},
+ 1: {"", maxInt, ""},
2: {"-", 10, ""},
3: {"gopher", 0, ""},
4: {"-", -1, "negative"},
5: {"--", -102, "negative"},
6: {string(make([]byte, 255)), int((^uint(0))/255 + 1), "overflow"},
- }
-
- for i, tt := range tests {
- err := repeat(tt.s, tt.count)
- if tt.errStr == "" {
- if err != nil {
- t.Errorf("#%d panicked %v", i, err)
- }
- continue
- }
+ })
- if err == nil || !Contains(err.Error(), tt.errStr) {
- t.Errorf("#%d expected %q got %q", i, tt.errStr, err)
- }
+ const is64Bit = 1<<(^uintptr(0)>>63)/2 != 0
+ if !is64Bit {
+ return
}
+
+ runTestCases("64-bit", []testCase{
+ 0: {"-", maxInt, "out of range"},
+ })
}
func runesEqual(a, b []rune) bool {