[imp] PDF thumbnails no longer working

Tue Oct 2 18:37:52 UTC 2018

Just recently, I noticed thumbnails for PDF attachments now show as a  
black questionmark on a white background. Other attachments (JPG files  
for instance) still show correct thumbnails, so I guess the imagick  
PECL extension is still doing its job.

imp = 6.2.22
Horde_Core = 2.31.6
Horde_Pdf = 2.0.7
php7-imagick = 3.4.3
ImageMagick = 7.0.8

Am I the only one where this seems to be broken?