cmd/webp-manual-test: blacklist some versions of the dwebp binary.
In particular, the 0.4.0 version of /usr/bin/dwebp that comes with
Ubuntu 14.04 LTS "Trusty", is known to be bad.
As per https://chromium.googlesource.com/webm/libwebp/+/master/NEWS
(grep for 239), versions 0.4.1 and 0.4.2 are also bad.
The alpha_color_cache.webp test file that triggers the discrepancy
between the (correct) Go implementation and the (buggy) libwebp C
implementation was added on 2015-01-23 in
https://chromium.googlesource.com/webm/libwebp-test-data/+/f64fb2da0175fb620540f076a4ba3d310b015a29
in response to https://bugs.chromium.org/p/webp/issues/detail?id=239
Change-Id: Ifee19be0af634b9bf36ff0e16957648e05be840a
Reviewed-on: https://go-review.googlesource.com/18186
Reviewed-by: David Crawshaw <crawshaw@golang.org>
diff --git a/cmd/webp-manual-test/main.go b/cmd/webp-manual-test/main.go
index c041e21..296c763 100644
--- a/cmd/webp-manual-test/main.go
+++ b/cmd/webp-manual-test/main.go
@@ -38,13 +38,9 @@
func main() {
flag.Parse()
- if *dwebp == "" {
+ if err := checkDwebp(); err != nil {
flag.Usage()
- log.Fatal("dwebp flag was not specified")
- }
- if _, err := os.Stat(*dwebp); err != nil {
- flag.Usage()
- log.Fatalf("could not find dwebp program at %q", *dwebp)
+ log.Fatal(err)
}
if *testdata == "" {
flag.Usage()
@@ -81,6 +77,25 @@
}
}
+func checkDwebp() error {
+ if *dwebp == "" {
+ return fmt.Errorf("dwebp flag was not specified")
+ }
+ if _, err := os.Stat(*dwebp); err != nil {
+ return fmt.Errorf("could not find dwebp program at %q", *dwebp)
+ }
+ b, err := exec.Command(*dwebp, "-version").Output()
+ if err != nil {
+ return fmt.Errorf("could not determine the dwebp program version for %q: %v", *dwebp, err)
+ }
+ switch s := string(bytes.TrimSpace(b)); s {
+ case "0.4.0", "0.4.1", "0.4.2":
+ return fmt.Errorf("the dwebp program version %q for %q has a known bug "+
+ "(https://bugs.chromium.org/p/webp/issues/detail?id=239). Please use a newer version.", s, *dwebp)
+ }
+ return nil
+}
+
// test tests a single WEBP image.
func test(name string) error {
filename := filepath.Join(*testdata, name)
