Update embedded org.osgi.util.tracker sources from 1.5.3 to 1.5.4

[HannesWell]

As requested in #18 (comment) (altough this does not resolve the entire issue) update embedded org.osgi.util.tracker sources from 1.5.3 to 1.5.4.

@tjwatson I simply copied the java files from https://repo1.maven.org/maven2/org/osgi/org.osgi.util.tracker/1.5.4/org.osgi.util.tracker-1.5.4-sources.jar and replaced the existing sources with that.

But since this mainly changes license headers and SPDX-License-Identifier, I wonder if this is the right way?
Btw. to we need a CQ for this then (it is already Eclipse licensed and from another Eclipse project)?

[github-actions]

Test Results

     24 files  ±0       24 suites  ±0   10m 43s ⏱️ - 1m 10s
2 150 tests ±0  2 105 ✔️ +1  45 💤 ±0  0 ❌  - 1 
2 194 runs  ±0  2 149 ✔️ +1  45 💤 ±0  0 ❌  - 1 

Results for commit 7cd6a2c. ± Comparison against base commit 3c1996e.

[tjwatson]

We shouldn't need a CQ for this.

[HannesWell]

We shouldn't need a CQ for this.

OK good, so is the change fine in total?

[merks]

FYI, in the dash logs for Obit I see an entry like this:

maven/mavencentral/org.osgi/org.osgi.util.tracker/1.5.4, Apache-2.0, approved, clearlydefined

[Torbjorn-Svensson]

Pardon a stupid question, but why do we need to duplicate the sources rather than have a dependency on the org.osgi.util.tracker delivery?

[tjwatson]

Pardon a stupid question, but why do we need to duplicate the sources rather than have a dependency on the org.osgi.util.tracker delivery?

The goal is to have an org.eclipse.osgi JAR that doesn't need any other JARs on the classpath to run. That goal could be achieve any number of ways. Historically it was most simple to just add the source to the project. Other motivations for tracker in particular was that frameworks were free to make optimizations to the implementation and integrate it more closely to the framework's service registry implementation.

I don't believe that we (nor felix) actually modify the tracker package anymore, but there are other classes in the OSGi Core specification that are modified (only in the implementation, otherwise we would fail signature tests from the OSGi compliance tests). Both Felix and Equinox include the Core specification source in our projects: https://github.com/apache/felix-dev/tree/master/framework/src/main/java/org/osgi

[HannesWell]

Thanks Tom and Ed.

I don't believe that we (nor felix) actually modify the tracker package anymore,

I assume that the Framework bundle cannot/musst not import packages from other bundles? So if the sources are not embedded the OSGi jar would have to be embedded.
I think that would be possible, but would probably require adjustments in the equinox Launcher since IIRC it does consider the Bundle-Classpath.
And in the end I see not much benefit from that at the moment.