Raise UnidentifiedImageError when opening TIFF without dimensions

[radarhere]

Resolves #8530

#8319 changed

xsize = int(self.tag_v2.get(IMAGEWIDTH))
ysize = int(self.tag_v2.get(IMAGELENGTH))

to

Pillow/src/PIL/TiffImagePlugin.py

Lines 1436 to 1440 in 82199ef

	xsize = self.tag_v2.get(IMAGEWIDTH)
	ysize = self.tag_v2.get(IMAGELENGTH)
	if not isinstance(xsize, int) or not isinstance(ysize, int):
	msg = "Invalid dimensions"
	raise ValueError(msg)

This change seems reasonable, especially when you consider #4103.

However, if IMAGEWIDTH or IMAGELENGTH were missing, then int(None) previously raised a TypeError. TypeErrors are caught when opening images

Pillow/src/PIL/Image.py

Lines 3497 to 3506 in 82199ef

	factory, accept = OPEN[i]
	result = not accept or accept(prefix)
	if isinstance(result, str):
	warning_messages.append(result)
	elif result:
	fp.seek(0)
	im = factory(fp, filename)
	_decompression_bomb_check(im.size)
	return im
	except (SyntaxError, IndexError, TypeError, struct.error) as e:

but the ValueErrors are not.

So this change inadvertently broke feeding a TIFF image to ImageFile.Parser, which relies on OSError (which UnidentifiedImageErrors are) to know that there isn't enough data yet.

Pillow/src/PIL/ImageFile.py

Lines 468 to 473 in 82199ef

	# attempt to open this file
	try:
	with io.BytesIO(self.data) as fp:
	im = Image.open(fp)
	except OSError:
	pass # not enough data

This PR changes the code to raise a TypeError again.

[jedie]

This is also a new error type that was not raised in past versions, isn't it? So i will also make trouble in Django...

[jedie]

Maybe it's a good idea to always raise a special error for all parsers, in all cases where the chunk data will not be enough to get the meta data and use RuntimeError as a base, because it's already catch?

[radarhere]

In 10.4.0, a TypeError would have been raised here by int(self.tag_v2.get(IMAGEWIDTH)) being run when there was no IMAGEWIDTH tag - effectively, int(None).

This is raising a TypeError again.

It is then caught in Image.open, and if no other formats think they can interpret the file, an UnidentifiedImageError is raised, which inherits from OSError, and is then caught in Parser.feed(), and the Django loop continues, unaware of the error.