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| author | go101 <tapir.liu@gmail.com> | 2024-05-03 09:56:47 +0000 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2024-05-03 12:58:37 +0000 |
| commit | 44b54b99c92e6023024e5219be8894a10a8a42fa (patch) | |
| tree | 9c01532f737d073728eac78c90fa3e6d0ce17866 /src/bytes | |
| parent | 2f5b420fb5984842afab37a9c2e66e6599107483 (diff) | |
| download | go-44b54b99c92e6023024e5219be8894a10a8a42fa.tar.xz | |
strings,bytes: improve Repeat panic messages
The Repeat("-", maxInt) call should produce
panic: runtime error: makeslice: len out of range
instead of
panic: strings: Repeat output length overflow
This PR is only for theory perfection.
Change-Id: If67d87b147d666fbbb7238656f2a0cb6cf1dbb5b
GitHub-Last-Rev: 29dc0cb9c9c63d8a008960b4527d6aa6798c1c17
GitHub-Pull-Request: golang/go#67068
Reviewed-on: https://go-review.googlesource.com/c/go/+/581936
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Diffstat (limited to 'src/bytes')
| -rw-r--r-- | src/bytes/bytes.go | 2 | ||||
| -rw-r--r-- | src/bytes/bytes_test.go | 47 |
2 files changed, 32 insertions, 17 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 { |