The surprisingly genial Halflings

[Ñólendil]

In Book II, Lothlórien, Haldir has some interesting comments for the Hobbits:

'But we have heard rumour of your coming, for the messengers of Elrond passed by Lórien on their way home up the Dimrill Stair. We had not hear of -- hobbits, of halflings, for many a long year, and did not know that any yet dwelt in Middle-earth. You do not look evil! And since you come with an Elf of our kindred, we are willing to befriend you, as Elrond asked; though it is not our custom to lead strangers through our land. But you must stay here tonight. How many are you?'

'You do not look evil'. Why would Haldir say that? Other characters like Boromir and Theoden were surprised to see Halflings because they thought them merely a part of fairy-story. But Haldir thought the Hobbits had died out, and knew of them before. They seem to have had an evil name. Or is there another interpretation?

Later he says:

'The four hobbits shall climb up here and stay with us -- we do not fear them! There is another talan in the next tree. There the others must take refuge.

In the Prologue for the Lord of the Rings Tolkien writes that

At no time had Hobbits of any kind been warlike, and they had never fought among themselves. In olden days they had, of course, been often obliged to fight to maintain themselves in a hard world; but in Bilbo's time that was very ancient history.

It seems highly unlikely to me that Hobbits of any kind would have fought the Elves of the Vales of Anduin.

So what's the meaning of Haldir's words: 'you do not look evil!'? Could they have had an (untrue) evil name in folklore? But Haldir's people had known Hobbits before.