Ensure that colors from registry are not null

[Christopher-Hermann]

The workbench colors will not always be initialized in the JFace area, for example if the workbench is not started. To make sure there are no NPE, the system colors are used as default.

Fixes #1955, eclipse-platform/eclipse.platform.swt#1275

[fedejeanne]

Maybe @iloveeclipse can take a look in Linux?

[iloveeclipse]

Maybe @iloveeclipse can take a look in Linux?

I can't currently start debugger due some obscure EMF problems. I will check once I've sorted out my EMF issue.

[github-actions]

Test Results

  605 files   -   605    605 suites   - 605   39m 31s ⏱️ - 12m 50s
7 664 tests ±    0  7 384 ✅  -    52  278 💤 + 50  2 ❌ +2 
8 051 runs   - 8 051  7 769 ✅  - 7 864  280 💤  - 189  2 ❌ +2 

For more details on these failures, see this check.

Results for commit 5f190d9. ± Comparison against base commit 521543f.

This pull request skips 50 tests.

UiTestSuite org.eclipse.ui.tests.api.ApiTestSuite org.eclipse.ui.tests.api.WorkbenchPluginTest ‑ testGetImageRegistryFromAdditionalDisplay
UiTestSuite org.eclipse.ui.tests.internal.InternalTestSuite org.eclipse.ui.tests.internal.TextHandlerTest ‑ testEditableText
org.eclipse.e4.ui.tests.workbench.HandlerActivationTest ‑ testHandlerInActivePartAndPerspective
org.eclipse.e4.ui.tests.workbench.HandlerActivationTest ‑ testHandlerInActivePartAndPerspectiveAndWindow
org.eclipse.e4.ui.tests.workbench.HandlerActivationTest ‑ testHandlerInActivePartAndWindow
org.eclipse.e4.ui.tests.workbench.HandlerActivationTest ‑ testHandlerInActivePartOnly
org.eclipse.e4.ui.tests.workbench.HandlerActivationTest ‑ testHandlerInActivePerspectiveAndWindow
org.eclipse.e4.ui.tests.workbench.HandlerActivationTest ‑ testHandlerInActivePerspectiveOnly
org.eclipse.e4.ui.tests.workbench.HandlerActivationTest ‑ testHandlerInWindowOnly
org.eclipse.e4.ui.tests.workbench.HandlerActivationTest ‑ testHandlerSwitchToInactivePart
…

[iloveeclipse]

This doesn't fix #1956 unfortunately.

[Christopher-Hermann]

This doesn't fix #1956 unfortunately.

Yes, for #1956 I need to dig into it further. Maybe it's better to revert the change if this is possible?

[iloveeclipse]

Maybe @iloveeclipse can take a look in Linux?

Still broken, see comments on #1956

[iloveeclipse]

Maybe it's better to revert the change if this is possible?

See comments on #1957.
If you can't fix all my issues today, we will revert.