handle nested jars/zips when stripping jars/zips

[tobias-hammerschmidt]

When jars are produced by eclipse pde build or eclipse tycho build its possible to bundle compiled classes and/or resources within nested jars. When using the reproducible-build-maven-plugin with such a jar the resulting stripped jar won't be reproducible since the plugin doesn't handle these nested jars. This pr adds handling for nested jars/zips.

[Zlika]

Thanks for this PR.
I see two main problems in this PR.
First, the diff is difficult to read because there are lots of cosmetic changes (maybe performed by an automatic formatting tool) unrelated with the feature. Please remove these changes from this PR. If you think these cosmetic changes improve the readability of the code, you can propose a dedicated PR to clean the code.
The second problem I see is that the code now processes and changes every embedded jar/zip files. However, most of the time embedded jar files are just external dependencies that we do not want to change (because it would change their hash/signature and then you cannot check their integrity anymore by comparison with the reference on maven central).
So not handling nested jar/zip files by default is done on purpose.
In theory, nested jars should be stripped before being incorporated inside another jar. Can't you do that in your tycho build? If you cannot do that, then you should add some configuration options in this plugin to explicitly enable the handling of some specific embedded jars, but you cannot blindly change all the nested jar/zip files.

[tobias-hammerschmidt]

Let me roll back the cosmectic changes which were introduced by some IDE autosave hook. Right now it is not possible to intercept the bundling within tycho since the nested jar as well as the final jar are packaged in a single step. I get your point regarding potential issues with nested third party dependencies. I'll update the code to handle stripping of nested jars/zips only for resources explicitly chosen by the user as part of the plugin configuration.

[Zlika]

Please rebase and force push to have a single commit with only the required changes.

[Zlika]

It would be nice to add an integration test for this feature... :-)

[tobias-hammerschmidt]

Here we go :-)

[Zlika]

Thank you. But I cannot see this library.jar file in the commit. Did you forget to add it?

[tobias-hammerschmidt]

The integration test mimics the behavior of a tycho build with nested jar so the library.jar is generated as part of the maven build (assembly plugin is called twice - first call to generate library.jar and second call to bundle the library.jar within the final artifact).

[Zlika]

ok fine, I didn't notice that.

[Zlika]

Thanks!

[tobias-hammerschmidt]

Thank you! Would you mind doing a release anytime soon? ;-)

[Zlika]

Yes. I would just want to replace the current travis build with github actions before doing a release. Maybe this week-end if I have some free time.

[Zlika]

@tobias-hammerschmidt v0.14 released!