File permissions/flags are ignored by filterdiff

[pbsds]

It seems filterdiff ignores changes in file permissions, such as removal of the executable flag.

Repro:

curl 'https://github.com/NationalSecurityAgency/ghidra/commit/e2a945624b74e5d42dc85e9c1f992315dd154db1.patch' | filterdiff

Expected result

A diff

Actual result

Nothing

[sergiomb2]

is a feature not a bug "This way filterdiff can be used to clean up an existing diff file, removing redundant lines
from the beginning (eg. the text from the mail body) or between the chunks (eg. in CVS diffs). To extract pure patch data"

[pbsds]

Not considering file permission changes (nor renames? #22) a part of the "patch data" strikes me as kind of arbitrary, and is unfortunate since it breaks the assumption that a filtered diff would apply the same changes as the original diff.

[sergiomb2]

correct filterdiff clean renames and file permissions modifications from the patch , is a almost an duplicate issue of #22