command: ..put( -local => "$fh",    -url => "$url/$base_dir/$work_dir"
+ )
Reply..:   put foo_Line_01
foo_Line_02
 failed

command: ..put( -local => \$fh,     -url => "$url/$base_dir/$work_dir"
+ )
Reply..:   put REF(0x274dc28) failed

command: ..put( -local => $fhref,   -url => "$url/$base_dir/$work_dir"
+ )
Reply..:   put REF(0x274dc28) failed 

command: ..put( -local => "\$fh",   -url => "$url/$base_dir/$work_dir"
+ )
Reply..:   put $fh failed

command: ..put( -local => "\$fhref",-url => "$url/$base_dir/$work_dir"
+ )
Reply..:   put $fhref failed
[download]

Any idea how to handle the -local parameter of the HTTP::DAV put request for an InMemoryfile linehandler?

Yes, sure. As I wrote:

HTTP::DAV documents for the put method:

One can upload/put a string by passing a reference to a scalar in the -local parameter.

Of course, to access the scalar behind IO::Scalar, you need to pass a reference to a scalar to the constructor IO::Scalar->new(), see IO::Scalar. BTW: You would pass the same reference to HTTP::DAV's put() method.

# (untested)
my $storage='';
my $handle=IO::Scalar->new(\$storage);
# use $handle to write to $storage here
my $dav=HTTP::DAV->new();
# set up $dav here
$dav->put(
    -local => \$storage,
    -url => 'http://www.example.com/davdemo/scalar.txt',
) or die "Put failed: ",join("\n",$dav->message(),$dav->errors());
[download]

Stringifying references ("$fh", "\$fh", "\$fhref") can't work, put() needs a reference to a scalar to transfer the scalar's content. But stringifying creates a string like "SCALAR(0x1c34ac0)" that put() will treat as a file name.

Also taking a reference to a reference won't work, you would at best transfer the stringified inner reference. Passing a reference to a handle won't work, as put expects a reference to a scalar (or a plain scalar containing a file name).

Update:

Your -url parameter for put() seems to be a directory. From a quick look at the sources of HTTP::DAV and HTTP::DAV::Resource,the -url parameter must be a filename if -local is a scalar reference. Else, HTTP::DAV will try to upload something that looks like a file to the DAV server to a resource that is a directory, not a file. Most likely, no sane DAV server will accept that. If you use put() with a local filename and a URL that points to a directory, HTTP::DAV will append the local filename (without directories) to the URL behind the scenes. This does not happen when -local is a reference to a scalar. A scalar reference simply does not have a filename that could be extracted and appended to the URL.

Alexander