cp of a source ending in /. copies the directory itself, not its contents

[Jaro-c]

podup cp payload/. SERVICE:/tmp should copy the contents of payload into /tmp, the way docker cp and podman cp treat a source ending in /.. It copies the directory itself instead, and the files land in /tmp/payload/.

Why

pack_path in internal/engine/copy/archive.rs names the archive's top entry with src.file_name(). Rust's Path drops a trailing . component, so Path::new("payload/.").file_name() is Some("payload"), and the tree is packed under payload/. Nothing on the way from the CLI to pack_path handles the /. suffix: I searched for it and found no match.

I found this by reading, during a review of #1790, and have not run it against a container yet. It is not introduced by #1790; it is on develop today.

What the fix needs

• Detect the trailing /. on the source as written, before it becomes a Path, since the Path has already lost it.
• Pack the directory's children at the top of the archive rather than under the directory's name.
• A live test in tests/engine_integration/cp_flags.rs that copies payload/. and asserts the files are at /tmp/a.txt, not /tmp/payload/a.txt, plus the same for the host direction if cp SERVICE:/path/. host has the same shape.

[Jaro-c]

Fixed in #1822, merged to develop as ea33e38. GitHub does not auto-close from a non-default branch, so closing by hand.

[Jaro-c]

Correction: the closing note on this issue and the commit message both say the container-to-host direction carries the same divergence. Measured on the published 5.9.5 binary against podman cp, in four cases (destination existing or not, source with and without the trailing /.), podup and podman agree in all four. That direction was never wrong. Details and the table are on #1830.