Fix partition copy in QoS [11451]

[jay-sridharan]

This PR fixes a bug where a QoS is copied from one ReaderProxyData to another but partition names are not copied if the list is empty.

Specifically, this code path:

/// src/cpp/rtps/builtin/discovery/participant/PDP.cpp   

         else
            {
                // Pool is not empty, use entry from pool
                ret_val = reader_proxies_pool_.back();
                reader_proxies_pool_.pop_back();
            }

            // Add to ParticipantProxyData
            (*pit->m_readers)[reader_guid.entityId] = ret_val;

[jay-sridharan]

@MiguelCompany

Hi Miguel,

I'm pretty new to this project, so please forgive the newbie questions. Do I need to assign reviewers to this somehow, or does that happen automatically? And should I worry about the CI failures? Seems like quite a few other PRs have failed CI as well.

Thanks for the great project!

[MiguelCompany]

@jay-sridharan First of all, thank you for your contribution. The process is that someone at eProsima reviews PRs, we will do it with yours soon. The CI failures seem unrelated to your changes, but checking them is also part of the review process.

[MiguelCompany]

The changes look good to me, but it would be great to have a regression test in place.
Would you mind adding one?

Also, while trying to find the root cause of the issue I've also found that these lines need a pit.second->clear() before the corresponding push_back

[jay-sridharan]

Thanks for the review! I'll look into adding a regression test. Any thoughts off the top of your head as to the best way to do that?

Probably set the resource limit to a single reader instance to limit the size of the pool, and then re-construct one and make sure the QoS was copied correctly? Perhaps there is an easier way

[JLBuenoLopez]

I have rebased and apply the review suggestion. Part of the changes suggested in this PR were already introduced in #2108. I have followed the same approach in the publisher's side.

[JLBuenoLopez]

@richiprosima please test this

Approved by EduPonz

[JLBuenoLopez]

@Mergifyio backport 2.10.x 2.9.x 2.6.x

[mergify]

backport 2.10.x 2.9.x 2.6.x

✅ Backports have been created

• #3610 Fix partition copy in QoS [11451] (backport #1947) has been created for branch 2.10.x
• #3611 Fix partition copy in QoS [11451] (backport #1947) has been created for branch 2.9.x
• #3612 Fix partition copy in QoS [11451] (backport #1947) has been created for branch 2.6.x