Will this switching down-regulator protect at all against short-circuits?

[(*steve*)]

I'm not following you. It sounds like you said NO and then YES: no it won't but it will "when shorted" and by "reducing the current". I'm confused. Here's an illustration:

(BATTERY) ---(connected to)---> Switching Regulator ----(connected to)---> GPS tracker

If the leads GOING TO the GPS tracker short or touch each other, what will happen to the BATTERY?

Let me offer an analogy...

It sounds like you say 1 and then 6. I can get as low as 1 when I roll the dice, or I can get as high as 6 when I roll the dice. I'm confused. Here's an illustration

(DICE)

When I throw the dice what number will come up?

There are a range of things that can happen. Yes, the device has a thermal shutdown, but that is intended to operate when the chip gets hot under a normal load (perhaps due to insufficient heatsinking). Under short circuit conditions, the datasheet says the device may be damaged. I gave you a possible (and indeed likely) failure scenario which in the right (or wrong) conditions could lead to pyrotechnic battery failure (an explosion).

Whether that would actually happen is uncertain. Perhaps something else could fail open circuit and it would just fail quietly and without much fuss.

A fuse is a good idea because it ensures that there is something which will fail open circuit. I concur with the 200 to 500mA rating above since the regulator (and the battery) are quite capable of more current than this and the fuse is thus almost guaranteed to fail if there is a fault which would exceed the current rating of the regulator.

 

[Gryd3]

There are a range of things that can happen. Yes, the device has a thermal shutdown, but that is intended to operate when the chip gets hot under a normal load (perhaps due to insufficient heatsinking). Under short circuit conditions, the datasheet says the device may be damaged. I gave you a possible (and indeed likely) failure scenario which in the right (or wrong) conditions could lead to pyrotechnic battery failure (an explosion).

Thermal shutdowns are not good enough for short circuit protection!
(Turn your tap water to hot, and you find it takes a while to warm up. At this point there is water everywhere and everything is ruined.)
The delay caused by waiting for it to heat up will allow damage to take place much easier... Use a fuse, or other protection method and take your time to re-read the suggestions put up here.