commitctx: extract all the manual logic to process the files
That branch of the if is significantly more complicated than the other two.
Moving it to its own function make it simple to keep the scope limited and to
read to the higher level function.
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true
[*.t]
indent_size = 2
indent_style = space
trim_trailing_whitespace = false