import org.eclipse.core.runtime.ILogListener;

import org.eclipse.core.runtime.IStatus;

	public void testBug308894() throws Throwable {

		FileEditorMapping newMapping = new FileEditorMapping("*.abc");

		assertNull(newMapping.getDefaultEditor());

		FileEditorMapping[] src = (FileEditorMapping[]) fReg.getFileEditorMappings();

		FileEditorMapping[] maps = new FileEditorMapping[src.length + 1];

		System.arraycopy(src, 0, maps, 0, src.length);

		maps[maps.length - 1] = newMapping;

		final Throwable[] thrownException = new Throwable[1];

		ILogListener listener = new ILogListener() {

			public void logging(IStatus status, String plugin) {

				Throwable throwable = status.getException();

				if (throwable == null) {

					thrownException[0] = new CoreException(status);

				} else {

					thrownException[0] = throwable;

				}

			}

		};

		Platform.addLogListener(listener);

		try {

			// invoke the same code that FileEditorsPreferencePage does

			((EditorRegistry) fReg).setFileEditorMappings(maps);

			((EditorRegistry) fReg).saveAssociations();

			PrefUtil.savePrefs();

		} finally {

			// undo the change

			((EditorRegistry) fReg).setFileEditorMappings(src);

			((EditorRegistry) fReg).saveAssociations();

			PrefUtil.savePrefs();

			Platform.removeLogListener(listener);

			if (thrownException[0] != null) {

				throw thrownException[0];

			}

		}

	}