Today I uploaded a new version of MRAWViewer to extras-devel.
Main changes over latest stable version in extras are:

• Added banners to inform user about what's going on when in fullscreen
• Previous / next image arrow buttons are real overlaid widgets now
• Image generated on-the-fly from RAW file when unable to decode embedded thumbnail
• Added ability to open supported RAW files with mrawviewer directly from the file manager
• Fixed bug #5419
• New image details management

If no major issue will come up, I'll promote it to testing in a few days, so please let me know!

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Luca Donaggio