Fix NullPointerException in ConfigCommand.diffOptions()

[moroten]

@Nullable FragmentOptionsForOutput options1 should be checked for being null before use. bazel config can otherwise crash, e.g. as the test configuration nowadays is trimmed.

[gregestren]

@sdtwigg

Interesting observation. Does this apply to both printing and diffing a configuration? i.e. both bazel config foo and bazel config foo bar?

[moroten]

I only tried bazel config foo bar for diffing and is now running my patched version ;)

[gregestren]

Do you mind trying bazel config foo too for one of the trimmed configs?

I don't know how familiar you are with the config command, but running it with no options shows all configs in the bazel process.

[moroten]

bazel config, bazel config foo and bazel config bar works, but bazel config foo bar crashes.

[gregestren]

I'm sorry, but to be clear, you mean on the unpatched version? If all of those work with your patch that's all I'm asking for. :)

[moroten]

Sorry for being unclear. I've now also run all four variants with both patched and unpatched version.
Unpatched version: bazel config, bazel config foo and bazel config bar works, but bazel config foo bar crashes.
Patched version: bazel config, bazel config foo, bazel config bar and bazel config foo bar all works.

Instead of crashing with NullPointerException, the patched version outputs:

Displaying diff between configs a8aaf8d028e4c9ba3ee0518043a87e8f514729d15df0ef0dd0f49bd0918cf512 and 9029ef98aed4ba5e0c34310cde7197acbdcf8a841fc6d5a90ca6303fd6d78a87
FragmentOptions com.google.devtools.build.lib.analysis.test.TestConfiguration$TestOptions {
  cache_test_results: null, AUTO
  coverage_report_generator: null, @bazel_tools//tools/test:coverage_report_generator
  coverage_support: null, @bazel_tools//tools/test:coverage_support
  experimental_cancel_concurrent_tests: null, false
  experimental_fetch_all_coverage_outputs: null, false
...
  trim_test_configuration: null, true
}

[gregestren]

Thanks so much!