mypy evaluates `files` config property relative to current working directory iso config file location

[domsj-foodpairing]

Bug Report

In #18482 support was added for walking up the file system to find the appropriate config file. I wanted to try this out, but ran into a problem.

The config file might contain a section files (and also exclude).
IMO the paths specified there should be considered relative to the location of the config file.

Instead mypy considers them relative to the current working directory (where mypy was invoked).
In order for the 'walk up' functionality to be useful the paths should be interpreted as relative to the config file location.

Actual Behavior

$ mypy
mypy: can't read file 'tests': No such file or directory

Your Environment

• Mypy version used: 1.15
• Mypy configuration options from mypy.ini (and other config files): files = tests