WebAPI: Do not wrap result if offset is invalid

[userwiths]

Closes #22158.

Description

On requests to /api/v2/torrents/info endpoint with an offset larger than the number of torrents, the offset defaults to 0 and returns results when its expected to return an error informing that this offset is out of range.

[glassez]

Could you summarize how it will behave after applying this patch?

Note that in the description of the PR, it is better to indicate how it will behave after merging it than just the problem itself (the description of the problem is generally redundant if there is a corresponding Issue to which it refers).

[userwiths]

Yeah sure.

I will write down a few example cases below, but the main gist is that if a (positive) limit and (whatever) offset are provided, we return a list of items that overlap offset; offset + limit and - size; size -1 where - size and 0 are the first torrent and size-1 is the last one. If there is no overlap, we return an empty list.

If (negative) limit is provided we return a list of all torrents with index > offset (if offset is negative or 0 that is all torrents, if its 0 < offset < size - 1 we return all with index > offset and if offset > size we return an empty list.

So ... lets say we have 5 torrents.

limit=1&offset=0 => returns the first torrent.
limit=1&offset=4 => returns the last torrent.
limit=1&offset=5 => returns empty list [].
limit=1&offset=-1 => returns last torrent.
limit=1&offset=-5 => returns the first torrent.
limit=1&offset=-6 => returns empty list [].
limit=2&offset=-6 => returns the first torrent.
limit=3&offset=-6 => returns first two torrents.
offset=-6 => returns all available torrents.
offset=6 => returns empty list [].

Hope this explanation is good enough .

[glassez]

IIRC, now it doesn't match the following part of OP:

expected to return an error informing that this offset is out of range.

[userwiths]

#22174 (comment)

It doesn't seem reasonable to make it an error in this case. If it is over-bound then returning an empty list would be enough IMO (as suggested in the linked issue #22158).

[glassez]

I just want to say about inconsistency between described expectations and end result. Either one or another should be adjusted.

P.S. I would just remove Description section from OP or replace it with description of how it is supposed to behave after merging this PR (as I suggested above).