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codefrau / SqueakJS

A Squeak Smalltalk VM in Javascript
https://squeak.js.org
MIT License
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PNG decoder bug: some forms are yellow #23

Closed marceltaeumel closed 10 months ago

marceltaeumel commented 9 years ago

squeakjs-vivide-forms

It could be an alpha-blending bug...

codefrau commented 9 years ago

Interesting. Would be great if you could isolate the problem (e.g. make a PNG or .morph that gets rendered in yellow when I drop it into a 4.5 image). Does it happen only on FireFox?

marceltaeumel commented 9 years ago

Those icons are yellow in Chrome, too.

marceltaeumel commented 9 years ago

yellow-bug-2

Here are more details. The creation of the form seems to be broken. Wrong bits.

marceltaeumel commented 9 years ago

Okay, seems to be that the primitive "primitivePixelValueAt" behaves differently in your VM.

marceltaeumel commented 9 years ago

Here is the cogIcon:

'iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAQAAAC1+jfqAAAABGdBTUEAAK/INwWK6QAAABl0 RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAAGSSURBVCjPVVFNSwJhEF78Ad79 Cf6PvXQRsotUlzKICosuRYmR2RJR0KE6lBFFZVEbpFBSqKu2rum6llFS9HHI4iUhT153n6Zt IWMOM+/MM88z7wwH7s9Ub16SJcnbmrNcxVm2q7Z8/QPvEOtntpj92NkCqITLepEpjix7xQti LOoQ2b6+E7YAN/5nfOEJ2WbKqOIOJ4bYVMEQx4LfBBQDsvFMhUcCVU1/CxVXmDBGA5ZETrhD CQVcYAPbyEJBhvrnBVPiSpNr6cYDNCQwo4zzU/ySckkgDYuNuVpI42T9k4gLKGMPs/xPzzov QiY2hQYe0jlJfyNNhTqiWDYBq/wBMcSRpnyPzu1oS7WtxjVBSthU1vgVksiQ3Dn6Gp5ah2YO KQo5GiuHPA6xT1EKpxQNCNYejgIR457KKio0S56YckjSa9jo//3mrj+BV0QQagqGTOo+Y7gZ If1puP3WHoLhEb2PjTlCTCWGXtbp8DCX3hZuOdaIc9A+aQvWk4ihq95p67a7nP+u+Ws+r0dq l9z/zv0NCYhdCPKZ7oYAAAAASUVORK5CYII='

Here is the printerIcon:

'iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAABGdBTUEAAK/INwWK6QAAABl0 RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAAJtSURBVDjLjZPfS1NhGMfPXfh3 OG/E/yBImNkqrYGCzAthh+WNgXihwQYb2CoYukGwsdRLoYUWQbRAhqzc2Q91IrrVhlhLqznL 5Tyb23m3s317z1szBzM68Lk47/N9Pud5XjgcAK7OVfM7/a2piE87HalRoLVHStrp1VKvLVi7 fE9wns/WaXi58UgoH4kl/CxIyOZ/cyRKSKRFmF/tw/B4p3jl7utLFwp6baHiySnBxheZUkHk M8HKrgSpUsVGWsaDN/tQG/1PLxT02EIlRbBJBZtfZaztlSF8JEgdFqBMdnh8im7LSqWpYHJy sqXHFiS5AkGMfi12UP0zRRm+D6fwxvPI0dWu3Q8QvV7f0iCgzQZKnl4WjqkgcVDDeyrYpqLo XoWtsbxTpLUyrlsFDA4O5vv7+w1MQBu7Z2dnEY1GcXsqjCwVJDM1JCixb1Vs0VXCdIoAXSVL BTcfhhEIBDA+Pg6NRtOtCLbpg0wmA7PZ/F8oWUEQMDAwsKsIiCzLUFhfX4coiv8kFAqhnh8b G6txFosFhBDG4uIiUqkUEzVDqc3Pz5/leZ4HZzKZkEgkGG63G8lkEn6/vylKxuFwnOU7OzvB TUxMwOfzMex2O+LxOJaWlpoSi8VgtVrP8u3t7eDoHvB6vQyXywV6Jwyj0YjR0VE2Zl9fH7q6 uqBWq9lZPd/W1gZuZGSk6vF42IHSuPD8JZbfBpvybOEFOjo6WHZubg6tra3gDAbDzNDQ0LZO pwPvCqNYIjg6IfhBOcxJSGdL2PtewKeMiKJUBu8MQ6VSKc1bFFPDv8C7ItXhJ2sYdv/lDmOV odR4Z6R6vucXuxIEyKz+W40AAAAASUVORK5CYII='

Decode it with:

Form fromBinaryStream: (Base64MimeConverter mimeDecodeToBytes: self printerIconContents readStream)
codefrau commented 9 years ago

Thanks for that test case!

(PNGReadWriter formFromStream: (Base64MimeConverter mimeDecodeToBytes:
'iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAABGdBTUEAAK/INwWK6QAAABl0
RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAAJtSURBVDjLjZPfS1NhGMfPXfh3
OG/E/yBImNkqrYGCzAthh+WNgXihwQYb2CoYukGwsdRLoYUWQbRAhqzc2Q91IrrVhlhLqznL
5Tyb23m3s317z1szBzM68Lk47/N9Pud5XjgcAK7OVfM7/a2piE87HalRoLVHStrp1VKvLVi7
fE9wns/WaXi58UgoH4kl/CxIyOZ/cyRKSKRFmF/tw/B4p3jl7utLFwp6baHiySnBxheZUkHk
M8HKrgSpUsVGWsaDN/tQG/1PLxT02EIlRbBJBZtfZaztlSF8JEgdFqBMdnh8im7LSqWpYHJy
sqXHFiS5AkGMfi12UP0zRRm+D6fwxvPI0dWu3Q8QvV7f0iCgzQZKnl4WjqkgcVDDeyrYpqLo
XoWtsbxTpLUyrlsFDA4O5vv7+w1MQBu7Z2dnEY1GcXsqjCwVJDM1JCixb1Vs0VXCdIoAXSVL
BTcfhhEIBDA+Pg6NRtOtCLbpg0wmA7PZ/F8oWUEQMDAwsKsIiCzLUFhfX4coiv8kFAqhnh8b
G6txFosFhBDG4uIiUqkUEzVDqc3Pz5/leZ4HZzKZkEgkGG63G8lkEn6/vylKxuFwnOU7OzvB
TUxMwOfzMex2O+LxOJaWlpoSi8VgtVrP8u3t7eDoHvB6vQyXywV6Jwyj0YjR0VE2Zl9fH7q6
uqBWq9lZPd/W1gZuZGSk6vF42IHSuPD8JZbfBpvybOEFOjo6WHZubg6tra3gDAbDzNDQ0LZO
pwPvCqNYIjg6IfhBOcxJSGdL2PtewKeMiKJUBu8MQ6VSKc1bFFPDv8C7ItXhJ2sYdv/lDmOV
odR4Z6R6vucXuxIEyKz+W40AAAAASUVORK5CYII=' readStream)) bits first hex

wrongly answers 16rFFFF00 instead of the correct 16rFFFFFF. It's neither ZipPlugin nor LargeIntegers plugin, happens even if I disable those.

codefrau commented 1 year ago

More clues:

up to 4.4: fine (https://squeak.js.org/run/#zip=https://files.squeak.org/4.4/Squeak4.4-12327.zip)

since 4.5: broken (https://squeak.js.org/run/#zip=https://files.squeak.org/4.5/Squeak4.5-13680.zip)

Filing in 4.4's PNGReadWriter>>copyPixelsRGB: fixes the issue.

Still not sure if it's an image bug or VM bug.

codefrau commented 10 months ago

Thanks to Agustin Martinez for isolating the bad BitBlt call!

It failed when a color map had negative shifts because it was accessed as a UInt32Array. The fix above makes it use an Int32Array instead.