[imp] PDF thumbnails no longer working

[Arjen de Korte]

Citeren Arjen de Korte <build+horde at de-korte.org>:

> 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?

Answering to myself: it turns out the distribution I use (openSUSE  
Tumbleweed) nowadays ships with a policy.xml file for ImageMagick that  
prevents reading PDF files. Changing the policy from 'none' to 'read'  
fixed the generation of thumbnails.