[KPhotoAlbum] Thumbnails missing with latest git

[Johannes Zarl]

To clarify and extend on my previous reply:


> You also write that your thumbnails stopped working between April and
> November, but the change w.r.t. on-demand building of thumbnails was last
> week or so...

I just realised you are talking about January 4 and January 11. That fits the 
changes. (See commit c8689d311250f8a672f0b18fa98f3cdcbd665c87 )


> > > With the "on-demand" thumbnails, they are built as they are requested
> > > (viewed). So the lag distributes to many small operations instead of one
> > > big. This way, KPA keeps being responsive with only small lags, which is
> > > surely a more desirable behavior. For local collections the lag should
> > > be
> > > that short that the user won't really notice the thumbnail building. So
> > > in this case it doesn't hurt, and for NFS users, it's far better.
> > 
> > On the other hand, this likely means it will be slower if I read in
> > several thousand new photos and want to quickly scroll through the new
> > thumbnails.  Is that correct? 

To clarify: even with incremental thumbnails, all thumbnails for newly found 
images are built from the new image finder. The difference is when you change 
the thumbnail size - in this case thumbnails are only built as needed if 
incremental thumbnails are enabled (which is the default).

> > Normally I load the images and wait for
> > the thumbnails to build.

I know that this is the workflow for many people - if this is broken, it is a 
definite bug.

Either way, you mentioned that the thumbnail view on your machine has a 
totally empty grid - that means something else must be broken, not just 
incremental thumbnailing. Since your thumbnail cache seems to be working again 
when you go back to a previous version, I suspect that the issue lies with 
thumbnail display rather than creation...

Can you check whether the bug was introduced before or after commit 
640a1e51a149d46b1e20dc29dffc5a7ba4fbf881 ?

Thanks,
  Johannes