urllib sets wrong Content-Length for pseudo files on Linux #93296
Description
Bug report
A value of the Content-length header returned by urllib.request.FileHandler.open_local_file may mismatch the length of data on Linux.
This happens when a file from a special file system (e.g., procfs or sysfs) is requested.
open_local_file relies on st_size; st_size is equal to zero for pseudo files on Linux.
Lines 1506 to 1511 in 8a0d9a6
Example
>>> import urllib.request
>>> url = "file:///proc/cpuinfo"
>>> handler = urllib.request.FileHandler()
>>> response = handler.file_open(urllib.request.Request(url))
>>> data = response.read()
>>> headers = response.info()
>>> assert int(headers["Content-length"]) == len(data)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AssertionError
>>> print(headers["Content-length"])
0
>>> print(len(data))
18294Your environment
- CPython versions tested on: 3.12.0 alpha 0
- Operating system and architecture: Linux