back-port: Null pointer check added for system package (#1455)

[gireeshpunathil]

Null pointer check added for system package

Hashtable does not store null values , so if systempackage comes as null it will throw null pointer exception

/cc @MohananRahul

[gireeshpunathil]

I get remote: error: GH006: Protected branch update failed for refs/heads/R4_31_maintenance. when I attempted to land this ( git push upstream R4_31_maintenance ). I don't want to use the GH UI button from an experience earlier where it did not record the committer name in the commit.
@HannesWell @akurtakov - any suggestions?

[merks]

Looking here, I see there needs to be a version increment for the project being changed.

https://ci.eclipse.org/pde/job/eclipse.pde/job/PR-1459/1/console

I.e., if the containing project is version 1.0.200, it should be incremented to 1.0.201, i.e., +1 on the micro/service version. Perhaps including features will also need such increments...

[gireeshpunathil]

@merks - thanks. looking at the CI log, the version upgradation is resolved now but new failure - not sure if it is related to infra. I am not sure if maintenance branch is well integrated into the build system

19:48:37  Exception in thread "Thread-3" java.lang.NoClassDefFoundError: org/eclipse/jgit/internal/JGitText
19:48:37  	at org.eclipse.jgit.internal.util.ShutdownHook.cleanup(ShutdownHook.java:85)
19:48:37  	at java.base/java.lang.Thread.run(Thread.java:840)
19:48:37  Caused by: java.lang.ClassNotFoundException: org.eclipse.jgit.internal.JGitText
19:48:37  	... 2 more
[Pipeline] }

[merks]

That jgit error is a very old one that is a bug in jgit and has no real build impact other than being annoying.

This looks like a "real error" where probably a version increment is needed:

<pre><code>MavenProject: org.eclipse.pde:org.eclipse.e4.tools.persistence.feature:1.1.300-SNAPSHOT @ /home/jenkins/agent/workspace/eclipse.pde_PR-1459/features/org.eclipse.e4.tools.persistence.feature/.polyglot.feature.xml: baseline and build artifacts have same version but different contents</code></pre>

Maybe @laeubi or @HannesWell will be better at "reading the tea leaves" here...

[HannesWell]

I get remote: error: GH006: Protected branch update failed for refs/heads/R4_31_maintenance. when I attempted to land this ( git push upstream R4_31_maintenance ). I don't want to use the GH UI button from an experience earlier where it did not record the committer name in the commit.

Using Rebase and merge is perfectly fine. Only Squash-and-merge caused trouble, but that's now disabled for PDE.