When opening files on a nfs mount the files are getting copied to my homedir (~/.fr-[randomhash]). This problem exists since the the ability to open files on gnome-vfs was introduced.

It looks like that copying the archive to homedir is necessary for files on for example a ssh remote location since unrar, unzip etc doesn't support files on a ssh remote location. But file-roller is threating files on a nfs mount exactly the same way, what is rather unnecessary. Because it takes a lot of time before a big archive is opened.

Extracting is really slow this way, since the file have to be copied to my home folder, get extracted and copied back.

I found out that the problem is in the following piece of code (file-utils.c line 1253):

gboolean
uri_is_local (const char *uri)
{
 GnomeVFSURI *vfs_uri;
 gboolean is_local;

 vfs_uri = new_uri_from_path (uri);
 g_return_val_if_fail (vfs_uri != NULL, FALSE);

 is_local = gnome_vfs_uri_is_local (vfs_uri);
 gnome_vfs_uri_unref (vfs_uri);

 return is_local;
}

gnome_vfs_uri_is_local says that a nfs url isn't local, what means that file-roller is threating it as a non local file. But file-roller should threat it as a local file, since nfs is mounted transparently.

I made the following change:
is_local = strcmp(gnome_vfs_uri_get_scheme (vfs_uri), "file") == 0;
Instead of using gnome_vfs_uri_is_local I check whether the scheme is equal to file. If the schema is file, the file could be transparently accessed by the filesystem so we could threat it like a local file.