MDEP-976: Fix artifact overwrites in copy-dependencies

[Ndacyayisenga-droid]

Fixes https://issues.apache.org/jira/browse/MDEP-976

cc @hboutemy

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[hboutemy]

@Ndacyayisenga-droid please take time to review the checkboxes in the issue description and fill them as necessary: keeping them not checked is not useful

on adding a new option just for copy-dependencies, I'm not clear: why?
prependGroupId is the configuration the user did not know about

I'd prefer either we change the default value for prependGroupId, or we add code to detect when conflict happens and WARN with a hint on how to configure prependGroupId

[hboutemy]

notice: IIUC, the conflict happens only when stripVersion is enable, isn't it?
then WARN if not stripVersion, because it warns about 2 groupIds that you can't really differentiate
and ERROR if this leads to overwrite, as it is better to fail the build than keep a silent conflicted file overwritten

WDYT of this behaviour poposal?

[cowwoc]

@hboutemy It's possible for two different artifacts to have the same artifactId and version even though their groupId is different, isn't it?

[Ndacyayisenga-droid]

notice: IIUC, the conflict happens only when stripVersion is enable, isn't it? then WARN if not stripVersion, because it warns about 2 groupIds that you can't really differentiate and ERROR if this leads to overwrite, as it is better to fail the build than keep a silent conflicted file overwritten

WDYT of this behaviour poposal?

@hboutemy this might cause a lot of build failures, especially in cases where two different artifacts share the same artifactId.
I'm not sure. Is it actually valid in Maven for two different artifacts to have the same artifactId but different groupIds?.

I tried to reproduce the issue in this projecct https://github.com/Ndacyayisenga-droid/mdep-976 (just execute the script).

results
Current version

For my snapshot