Link to provider does not work with full view of image

Yes, there is definitely something wrong.
For me it looks like 'Image Preview Settings' is overwriting 'Full size display settings' and 'Thumbnail'.
It is not possible to set thumbnail to be linked to content and full size image to provider at the moment, you can only have both linked to content or both linked to provider.

It's definitely a bug.

The problem is in emimage.theme.inc. It looks like a sloppy copy/paste job. The same line that is appropriate for theming preview links is used for full and thumbnail links as well.

$link = isset($options['preview_link']) ? $options['preview_link'] : $field['widget']['preview_link'];

It's pretty straightforward to fix. Just change the word 'preview' to 'full' or 'thumbnail' in each place. Patch attached.

Hey gilgabar

Your patch is giving "patch unexpectedly ends in middle of line" error because it's missing a return character at end of file.

After adding that return character, the patch worked and it solved the issue for me.

fixed. thanks @gilgabar.