pkg/copy: add tests for ParseSourceAndDestination

[ROKUMATE]

Fixes: #28907

What

Add unit tests for ParseSourceAndDestination in pkg/copy, the parser behind
podman cp arguments ([nameOrID:]path). It had no test coverage.

Why

The parsing rules are easy to regress: a leading .// keeps a colon as part
of the path (not a container ref), absolute paths never denote a container, and
both paths must be non-empty. Tests lock this behavior in.

Details

Table-driven tests in pkg/copy/parse_test.go covering:

• container source -> local dest, and the reverse
• colon inside a path that starts with . or /
• a relative path with no colon (no container)
• error cases: missing source path, missing dest path, both empty

No production code changes. go test ./pkg/copy/ passes in local run.

[packit-as-a-service]

tmt tests failed for commit e0a8980. @lsm5, @psss, @thrix please check.

[ROKUMATE]

@Honny1 @danishprakash can you help me with the review of this pr as well
i am not sure why the ci are failing here as the tests i wrote and ci issue are not related acc. to me
also the test passed on local run

[Honny1]

Can you please add Fixes: #issueNumber to the commit msg? Otherwise LGTM.

[Honny1]

Packit is unstable.

[ROKUMATE]

ohkk will do it thanks for review

[packit-as-a-service]

tmt tests failed for commit ba72933. @lsm5, @psss, @thrix please check.

[Honny1]

/packit rebuild-failed

[ROKUMATE]

@danishprakash, @Honny1 the issue is up from a week if any points i have missed solving it do point it out ... so i will solve it or if the pr is invalid for current time then i will try solving other bugs ...

[Honny1]

I'm missing some edge cases:

• Multiple colons: ctr:/path/with:colon should split only on the first colon
• No container on either side: two local paths like /src, /dst (function allows it despite docstring)
• Container on both sides: a:/x, b:/y (function allows it, no validation)
• Bare filename: myfile.txt with no colon, dot, or slash prefix
• Whitespace in path: ctr:/path with spaces/file
• Source only empty, destination valid: "", /dst (distinct from "both empty")

Otherwise LGTM

[ROKUMATE]

Resolved the additional test cases that you mentioned sir 👍🏼

[Honny1]

LGTM

[Honny1]

PTAL @podman-container-tools/podman-maintainers @podman-container-tools/podman-reviewers

[inknos]

LGTM, something's up with the tests but seems unrelated

Edit: my bad, Matt said it right

[mheon]

I think the test failures are legitimate. I bet you it's because the tests use forward-slash and, on Windows, our parsing wants backslashes?