Add capability and requirement for org.eclipse.equinox.internal.p2.repository.Transport

[trancexpress]

Fixes: #971

[trancexpress]

I can run the test fine with the 2 changes here.

[trancexpress]

Fail on Linux is:

Error:  The projects in the reactor contain a cyclic reference: Edge between 'Vertex{label='org.eclipse.platform:org.eclipse.equinox.p2.transport.ecf:1.4.600-SNAPSHOT'}' and 'Vertex{label='org.eclipse.platform:org.eclipse.equinox.p2.repository:2.9.500-SNAPSHOT'}' introduces to cycle in the graph org.eclipse.platform:org.eclipse.equinox.p2.repository:2.9.500-SNAPSHOT --> org.eclipse.platform:org.eclipse.equinox.p2.transport.ecf:1.4.600-SNAPSHOT --> org.eclipse.platform:org.eclipse.equinox.p2.repository:2.9.500-SNAPSHOT -> [Help 1]

Looks like the transport bundle requires the repository bundle, which needs the service:

Bundle-SymbolicName: org.eclipse.equinox.p2.transport.ecf
[..]
 org.eclipse.equinox.p2.repository;bundle-version="2.1.0",

[github-actions]

Test Results

0 files   -   384  0 suites   - 384   0s ⏱️ - 41m 16s
0 tests  - 1 907  0 ✅  - 1 904  0 💤  - 3  0 ❌ ±0 
0 runs   - 6 721  0 ✅  - 6 712  0 💤  - 9  0 ❌ ±0 

Results for commit a7b228f. ± Comparison against base commit d20f70b.

[laeubi]

@trancexpress I'll need to look into this I think it is a general Tycho problem and we likely want a generic solution for this as we have for p2.inf already!

[laeubi]

@trancexpress as the Eclipse is now in RC1 phase and I want to publish a Tycho release soon I would like to postpone this (and the Tycho change) to the next release I assume this is not critical here as one can always manually add the required dependency.

[trancexpress]

Sure, no rush here.

[laeubi]

This does not look correct, usually the namespace should match the filter see

https://docs.osgi.org/specification/osgi.cmpn/7.0.0/service.namespaces.html#service.namespaces-osgi.implementation.namespace

Also I'm not sure if implementation is a good choice, if we look at how P2 implements this, the osgi service namespace seems a better fit (and we can automate this in the future hopefully to not write these on our own):

https://docs.osgi.org/specification/osgi.cmpn/7.0.0/service.namespaces.html#service.namespaces-osgi.service.namespace

So what we do here is providing an IAgentService with the given property and I would say it must be

osgi.service;objectClass:List<String>="org.eclipse.equinox.p2.core.spi.IAgentServiceFactory";p2.agent.servicename="org.eclipse.equinox.internal.p2.repository.Transport"

@tjwatson can you verify? Sadly the OSGi spec is a bit short on this with examples :-\