previewjob: use contains instead of supportsMimetype
supportsMimetype
takes inheritance into account, and this can
cause issues where some mimetype gets ignored by its own thumbnailer.
For example, application/x-tiled-tmx
does have it's own
thumbnailer, but since we took inheritance into account with supportsMimetype
, that would make application/x-tiled-tmx
resolve into xml
files, and it's own thumbnailer would not get used
after all.
Using plugin.mimeTypes().contains(mime)
is more specific and avoids inheritance issues.
For optimal results, we should also merge network/kio-extras!367 (merged)
Edited by Akseli Lahtinen