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/AbstractOperation.java
* @see org.eclipse.core.commands.operations.IUndoableOperation#canRedo()
	 */
	public boolean canRedo() {
		return true;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IUndoableOperation#canUndo()
	 */
	public boolean canUndo() {
		return true;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IUndoableOperation#dispose()
	 */
	public void dispose() {
		
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IUndoableOperation#execute(org.eclipse.core.runtime.IProgressMonitor, org.eclipse.core.runtime.IAdaptable)
	 */
	public abstract IStatus execute(IProgressMonitor monitor, IAdaptable info);
	public IUndoContext[] getContexts() {
		return (IUndoContext[]) fContexts.toArray(new IUndoContext[fContexts
				.size()]);