Segmentation fault when creating gradient images with mode "F"

[derhintze]

What did you do?

Python 3.9.1 (default, Jan 13 2021, 15:21:08) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import PIL
>>> print(PIL.__version__)
8.0.1
>>> import PIL.Image as pimage
>>> image1 = pimage.linear_gradient("L")
>>> image2 = pimage.linear_gradient("F")
Segmentation fault

What did you expect to happen?

Not segfaulting.

What actually happened?

Segfaulted.

What are your OS, Python and Pillow versions?

• OS: Red Hat 4.8.5-44
• Python: Python 3.9.1
• Pillow: 8.0.1

[derhintze]

note that the following works:

>>> import PIL.Image as pimage
>>> image1 = pimage.linear_gradient("L")
>>> image2 = image1.convert("F")

[radarhere]

I've created #5274 to resolve this.