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/ObjectUndoContext.java
* @see org.eclipse.core.commands.operations.IUndoContext#getLabel()
	 */
	public String getLabel() {
		if (label == null)
			return object.toString();
		return label;
	}
	/**
	 * Return the object that is represented by this context.
	 * 
	 * @return - the object represented by this context.
	 */
	public Object getObject() {
		return object;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IUndoContext#getOperationApprover()
	 */
	public IContextOperationApprover getOperationApprover() {
		return approver;
	}
	/**
	 * Set the IContextOperationApprover that approves the undo or redo of
	 * operations that have this context.
	 * 
	 * @param approver -
	 *            the operation approver to be used for this context
	 */