On Tue, Jun 11, 2013 at 11:12 PM, Glenn Morris <rgm@gnu.org> wrote:
Stefan Monnier wrote:

>> The idea seems fine, but as written it won't work without requiring
>> cl-lib at run-time.
>
> That's fine for non-preloaded packages.

I meant that image-dired does not presently require cl-lib at runtime,
so to be a complete solution the patch should have included that change
too.
 
Basically, whenever a line contains an overlay and this function is evoked, it thinks it already has a thumbnail, and won't put a new one there.

I can rewrite the function so it doesn't use cl-remove-if-not, although I assumed that avoidance of the execution/expansion distinction was one of the reasons cl-lib was created.

Evgeni