Bug 84446 OperationHistory should protect itself better against runtime exceptions
Since clients of the history might rely on getting certain events even if a operation causes runtime exceptions (for example listeners) the history should protect itself better agains runtime exceptions. This envloves: - listeners causing runtime exceptions in the call back - Operation execution causing runtime exceptions. In this case listeners must be informed as well.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/DefaultOperationHistory.java
*/
	public IStatus redoOperation(IUndoableOperation operation, IProgressMonitor monitor, IAdaptable info) throws ExecutionException {
		Assert.isNotNull(operation);
		IStatus status;
		if (operation.canRedo()) {
			status = getRedoApproval(operation, info);
			if (status.isOK()) {
				status = doRedo(monitor, info, operation, false);
			}
		} else {
			status = OPERATION_INVALID_STATUS;
		}
		return status;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IOperationHistory#remove(org.eclipse.core.commands.operations.IUndoableOperation)
	 */
	public void remove(IUndoableOperation operation) {
		if (fUndo.contains(operation)) {
			fUndo.remove(operation);
			internalRemove(operation);
		} else if (fRedo.contains(operation)) {
			fRedo.remove(operation);
			internalRemove(operation);
		}
	}
	/*
	 * (non-Javadoc)