diff options
| -rw-r--r-- | app/javascript/mastodon/utils/resize_image.js | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/app/javascript/mastodon/utils/resize_image.js b/app/javascript/mastodon/utils/resize_image.js index bbdbc865e..a8ec5f3fa 100644 --- a/app/javascript/mastodon/utils/resize_image.js +++ b/app/javascript/mastodon/utils/resize_image.js @@ -67,6 +67,14 @@ const processImage = (img, { width, height, orientation, type = 'image/png' }) = context.drawImage(img, 0, 0, width, height); + // The Tor Browser and maybe other browsers may prevent reading from canvas + // and return an all-white image instead. Assume reading failed if the resized + // image is perfectly white. + const imageData = context.getImageData(0, 0, width, height); + if (imageData.every(value => value === 255)) { + throw 'Failed to read from canvas'; + } + canvas.toBlob(resolve, type); }); |