[PNG] IndexError is raised when the sRGB chunk is broken #6430
Description
What did you do?
from PIL import Image
import io
# assumes the current directory is the root of this repository.
with open('Tests/images/imagedraw_polygon_1px_high.png', 'rb') as f:
data = bytearray(f.read())
# insert the sRGB chunk after the IDAT chunk. Its length, chunk type and crc are valid, but the sRGB chunk should contain more data.
data[61:61] = b"\x00\x00\x00\x00sRGB\x10\x1c\xd3\xce"
# IndexError is raised
with Image.open(io.BytesIO(data)) as img:
img.load()What did you expect to happen?
IndexError is a little conusing. Maybe ValueError is better.
What actually happened?
Traceback (most recent call last):
File "issue_index_error_simplified.py", line 14, in <module>
img.load()
File "/usr/local/lib/python3.8/dist-packages/PIL/ImageFile.py", line 268, in load
self.load_end()
File "/usr/local/lib/python3.8/dist-packages/PIL/PngImagePlugin.py", line 978, in load_end
self.png.call(cid, pos, length)
File "/usr/local/lib/python3.8/dist-packages/PIL/PngImagePlugin.py", line 202, in call
return getattr(self, "chunk_" + cid.decode("ascii"))(pos, length)
File "/usr/local/lib/python3.8/dist-packages/PIL/PngImagePlugin.py", line 512, in chunk_sRGB
self.im_info["srgb"] = s[0]
IndexError: index out of range
What are your OS, Python and Pillow versions?
- OS: ubuntu:focal-20220426
- Python: 3.8.10
- Pillow: 9.2.0