Solid server ignores content type

Start by tracing how the Solid server handles the PUT and subsequent GET for resources whose filenames have no recognized extension, using the request and response examples in this issue. Reproduce the upload with Content-Type image/jpeg and verify that the resource is served as image/jpeg rather than text/turtle and is classified consistently with the uploaded content.

I have tried to upload various images to my POD and at some point I named it "x-jpg" instead of "x.jpg". It turns out that the solid server uses the filename extention to detect content type instead of relying on the actual content type.

Here is an example PUT operation showing the name "...270-jpg" and the content-type "image/jpeg":

PUT https://elfisk.solid.community/public/solidrc/images/Billede-30-10-2018-20.01.20-1541949270-jpg HTTP/1.1
Host: elfisk.solid.community
Connection: keep-alive
Content-Length: 257876
authorization: Bearer XXX
Origin: https://localhost:5001
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36
content-type: image/jpeg
Accept: */*
Referer: https://localhost:5001/Home/Models
Accept-Encoding: gzip, deflate, br
Accept-Language: da-DK,da;q=0.9,en-US;q=0.8,en;q=0.7,sv;q=0.6,nb;q=0.5
Cookie: connect.sid=XXX

Later on I do a GET on https://elfisk.solid.community/public/solidrc/images/ which returns the document below. You can see that ".jpg" files have type "jpeg:Resource" whereas the "-jpg" files does not.

@prefix : <#>.
@prefix im: <>.
@prefix ldp: <http://www.w3.org/ns/ldp#>.
@prefix terms: <http://purl.org/dc/terms/>.
@prefix XML: <http://www.w3.org/2001/XMLSchema#>.
@prefix st: <http://www.w3.org/ns/posix/stat#>.
@prefix jpeg: <http://www.w3.org/ns/iana/media-types/image/jpeg#>.

im:
    a ldp:BasicContainer, ldp:Container;
    terms:modified "2018-11-11T15:14:19Z"^^XML:dateTime;
    ldp:contains
        <Billede-30-10-2018-19.52.49-1541949020.jpg>,
        <Billede-30-10-2018-20.01.20-1541949270-jpg>;
    st:mtime 1541949259.98;
    st:size 4096.
<Billede-30-10-2018-19.52.49-1541949020.jpg>
    a jpeg:Resource, ldp:Resource;
    terms:modified "2018-11-11T15:10:11Z"^^XML:dateTime;
    st:mtime 1541949011.912;
    st:size 249480.
<Billede-30-10-2018-20.01.20-1541949270-jpg>
    a ldp:Resource;
    terms:modified "2018-11-11T15:14:22Z"^^XML:dateTime;
    st:mtime 1541949262.852;
    st:size 257876.

Later on the data browser goes beserk when you try to delete the "*-jpg" image as it is served as a turtle document:

GET https://elfisk.solid.community/public/solidrc/images/Billede-30-10-2018-20.01.20-1541949270-jpg HTTP/1.1

HTTP/1.1 200 OK
X-Powered-By: solid-server
Link: <Billede-30-10-2018-20.01.20-1541949270-jpg.acl>; rel="acl", <Billede-30-10-2018-20.01.20-1541949270-jpg.meta>; rel="describedBy", <http://www.w3.org/ns/ldp#Resource>; rel="type"
Content-Type: text/turtle