Output of restic version

restic 0.18.0 compiled with go1.24.1 on linux/amd64

What backend/service did you use to store the repository?

Backblaze B2 and Local.

Problem description / Steps to reproduce

$ export RESTIC_PASSWORD=secret
$ restic -q init -r /tmp/repo
$ echo test | restic -q backup -r /tmp/repo --stdin --stdin-filename $PWD/test.txt
Fatal: unable to save snapshot: open /home: no such file or directory

Using --stdin-filename /test.txt or ---stdin-filename test.txt instead works.

Expected behavior

It would be nice if --stdin-filename /path/text.txt worked like it did up to version 0.17.3.