fix: web seed request URLs (#2267)

* fix: web seed request URLs

When adding a multi torrent file (not magnet link) which has only web seeds, the torrent fails to download because webtorrent seems to try to call the wrong URL.

Suppose that we are using the default download path of `/tmp/webtorrent`, and we have a web seed at `https://some-s3-bucket.s3.amazonaws.com/my-torrent` where `my-torrent` contains some nested directory structure like this:

```
my-torrent/
    file1.txt
    file2/
        file2.txt
```

Webtorrent will attempt to fetch the following URLs:

```
https://some-s3-bucket.s3.amazonaws.com/my-torrent//tmp/webtorrent/my-torrent/file1.txt
https://some-s3-bucket.s3.amazonaws.com/my-torrent//tmp/webtorrent/my-torrent/file2/file2.txt
```

This is obviously incorrect, but perhaps I'm doing something wrong to cause this. I dug through the code, and it seems that `fs-chunk-store` is [modifying `file.path`](https://github.com/webtorrent/fs-chunk-store/blob/master/index.js#L48) when the [chunk store is created](https://github.com/webtorrent/webtorrent/blob/master/lib/torrent.js#L485). Stripping off the temp path fixes this issue and the download progresses as expected.

* Update lib/webconn.js

Co-authored-by: Diego Rodríguez Baquero <github@diegorbaquero.com>

Co-authored-by: Diego Rodríguez Baquero <github@diegorbaquero.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/webconn.js b/lib/webconn.js
index bd306f6..b1170a6 100644
--- a/lib/webconn.js
+++ b/lib/webconn.js
@@ -102,7 +102,7 @@ class WebConn extends Wire {
         const fileEnd = requestedFile.offset + requestedFile.length - 1
         const url = this.url +
           (this.url[this.url.length - 1] === '/' ? '' : '/') +
-          requestedFile.path
+          requestedFile.path.replace(this._torrent.path, '')
         return {
           url,
           fileOffsetInRange: Math.max(requestedFile.offset - rangeStart, 0),