Add decompression bomb check to grabclipboard() on Windows

[radarhere]

At the moment, grabclipboard() on Windows may bypass Image.open() when loading the image data.

Pillow/src/PIL/ImageGrab.py

Lines 184 to 192 in 7cb0e02

	data = io.BytesIO(data)
	if fmt == "png":
	from . import PngImagePlugin
	return PngImagePlugin.PngImageFile(data)
	elif fmt == "DIB":
	from . import BmpImagePlugin
	return BmpImagePlugin.DibImageFile(data)

This means that they avoid running

Pillow/src/PIL/Image.py

Line 3687 in 7cb0e02

_decompression_bomb_check(im.size)

Switching to Image.open() adds this check.

[akx]

LGTM. A couple of comment suggestions to make the life of future reviewers a bit easier?

[akx]

Suggested change

	LPCSTR format_names[] = {"DIB", "DIB", "file", "PNG", NULL};
	// Pillow format names in the same order as the formats above
	LPCSTR format_names[] = {"DIB", "DIB", "file", "PNG", NULL};

[radarhere]

...they're not exactly 'Pillow format names'. 'DIB' and 'PNG are, but 'file' isn't.

[akx]

Fair:

Suggested change

	LPCSTR format_names[] = {"DIB", "DIB", "file", "PNG", NULL};
	// Names known by ImageGrab.py in the same order as the formats above
	LPCSTR format_names[] = {"DIB", "DIB", "file", "PNG", NULL};

[radarhere]

I've pushed a similar comment, that connects it clearly to the variable in ImageGrab.py.