Support following symbolic links to files

[mirabilos]

This implements the necessary support to allow plexus-archiver to archive the contents of symlinks (instead of the symbolic links themselves), depending on the (already-extant) follow-symlinks flag.

Closes: #37

I’ve tested this in a patch against 3.2.0 which slightly differs from this patch against git master, but I believe there to be no issues.

[plamentotev]

I think f.getCanonicalPath() would do the same without introducing Path.

[plamentotev]

This is true by default isFollowingSymLinks. I'm a bit concerned that this change would change the behavior of existing applications. I know the existing behavior is odd, but it was existing for quite some time and maybe there are applications that depend on it. Do you think adding additional flag would made sense? In general I hate fix bug kind of flags, but this code was here for quite some time and maybe there is code out there depending on PlexusIoFileResourceCollection not following symlinks by default.

[plamentotev]

Adding a test case would be great if you have the time.

@mirabilos thanks for the contribution. The symbolic link handling in Plexus IO and Plexus Archiver could be improved, it is great to see contributors helping with that,

[mirabilos]

Plamen Totev dixit:

I think `f.getCanonicalPath()` would do the same without introducing `Path`.

Hrm. It does say it follows symlinks on Unix… (I hope it also does that on Windows… ouch, we’ll probably have to test that…)

[mirabilos]

Plamen Totev dixit:

Adding a test case would be great if you have the time.

I’m very much out of my depth here. I don’t use this directly, but as… <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-source-plugin</artifactId> <version>${maven.source.version}</version> <dependencies> <dependency> <!-- codehaus-plexus/plexus-archiver#160 --> <groupId>org.evolvis.tartools.forked</groupId> <artifactId>plexus-archiver</artifactId> <version>4.2.1</version> </dependency> </dependencies> </plugin> … so the only testcase I have is a full project. ***@***.*** thanks for the contribution. The symbolic link handling in

@plexus IO and Plexus Archiver could be improved, it is great to see

***@***.*** helping with that, Thanks. Unfortunately I’ve very little experience with developing Maven itself, and I basically took that suggestion from the comment codehaus-plexus/plexus-archiver#47 (comment) and hacked on it until I got it. I’m not really in a situation to bring it further. bye, //mirabilos -- Infrastrukturexperte • tarent solutions GmbH Am Dickobskreuz 10, D-53121 Bonn • http://www.tarent.de/ Telephon +49 228 54881-393 • Fax: +49 228 54881-235 HRB AG Bonn 5168 • USt-ID (VAT): DE122264941 Geschäftsführer: Dr. Stefan Barth, Kai Ebenrett, Boris Esser, Alexander Steeg

[mirabilos]

Plamen Totev dixit:

This is `true` by default `isFollowingSymLinks`. I'm a bit concerned

I think it even *should* be true. It’s a breaking change, yes, so a major version bump is necessary (see the other mail).

[Copilot]

Pull Request Overview

This PR adds support for following symbolic links when archiving files by leveraging the existing follow-symlinks flag. When enabled, the archive will contain the actual file contents that symlinks point to rather than the symbolic links themselves.

Key changes:

• Modified file resource collection to resolve symbolic links to their real paths when the follow-symlinks flag is enabled
• Refactored FileAttributes constructor to accept Path objects directly, enabling symlink resolution

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
PlexusIoFileResourceCollection.java	Resolves symbolic links to real paths when follow-symlinks is enabled before creating file attributes
FileAttributes.java	Adds new constructor accepting Path parameter to support resolved symlink paths

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[Copilot]

toRealPath() requires LinkOption varargs but none are provided. When following symlinks, this will throw NoSuchFileException if the symlink target doesn't exist. Consider adding exception handling or using toRealPath(LinkOption.NOFOLLOW_LINKS) with custom symlink resolution logic to provide better error messages when symlink targets are missing.

Suggested change

	p = p.toRealPath();
	try {
	p = p.toRealPath();
	} catch (java.nio.file.NoSuchFileException e) {
	throw new IOException("Symlink target does not exist for: " + p.toString(), e);
	}