SuccessChanges

Summary

  1. [SPARK-24319][SPARK SUBMIT] Fix spark-submit execution where no main (commit: 18cb0c07988578156c869682d8a2c4151e8d35e5) (details)
Commit 18cb0c07988578156c869682d8a2c4151e8d35e5 by vanzin
[SPARK-24319][SPARK SUBMIT] Fix spark-submit execution where no main
class is required.
## What changes were proposed in this pull request?
With [PR 20925](https://github.com/apache/spark/pull/20925) now it's not
possible to execute the following commands:
* run-example
* run-example --help
* run-example --version
* run-example --usage-error
* run-example --status ...
* run-example --kill ...
In this PR the execution will be allowed for the mentioned commands.
## How was this patch tested?
Existing unit tests extended + additional written.
Author: Gabor Somogyi <gabor.g.somogyi@gmail.com>
Closes #21450 from gaborgsomogyi/SPARK-24319.
(commit: 18cb0c07988578156c869682d8a2c4151e8d35e5)
The file was modifiedlauncher/src/main/java/org/apache/spark/launcher/Main.java (diff)
The file was modifiedlauncher/src/test/java/org/apache/spark/launcher/SparkSubmitCommandBuilderSuite.java (diff)
The file was modifiedlauncher/src/main/java/org/apache/spark/launcher/SparkSubmitCommandBuilder.java (diff)