Is Honesty more important than being polite?

Over the years it has come to my attention that some individuals in this world are extremely honest, despite the negative impact it can have on others. I consider myself an honest person but believe in what are sometimes called ‘white lies’ for the purposes of being polite. A common example here would be attending dinner at one’s house and thanking them for dinner, stating it was good, when in fact it was horrible. Or holding the door for someone and when they say thank you, I respond “it was my pleasure”. I feel these are barely lies or even half truths as they have little to no negative impact (except to me) and serve as a social lubricant. I am quite close with someone who believes all forms of dishonesty should be avoided. In fact, she will tell me I am being dishonest if I tell my host I enjoyed dinner when I did not. She will tell her host just how bad dinner was, or how bad an idea one has is regardless of the impact on her audience. Based on these examples, I ask you, in terms of ethics, where does one draw the line between honesty and politeness?