PIL fails to roundtrip some TIFF images #1039
Description
For some TIFF images, a simple Image.open(path).save(path) fails with the following:
_TIFFVSetField: /path/to/test.tiff: Bad value 2 for "ExtraSamples" tag.
Traceback (most recent call last):
<elided traceback>
File "/usr/lib/python3.4/site-packages/PIL/Image.py", line 1685, in save
save_handler(self, fp, filename)
File "/usr/lib/python3.4/site-packages/PIL/TiffImagePlugin.py", line 1185, in _save
e = Image._getencoder(im.mode, 'libtiff', a, im.encoderconfig)
File "/usr/lib/python3.4/site-packages/PIL/Image.py", line 430, in _getencoder
return encoder(mode, *args + extra)
RuntimeError: Error setting from dictionary
The image was created using Qt's QImageWriter (from a QImage.Format_RBG32 image), but it is not clear how to reproduce the issue as a simple blank image created in the same way does not trigger the same issue.