Comment 18 for bug 858957

>> As for other viewers, PDF also does embedded annotations/bookmarks.

> It may, but I doubt that PDF viewers save annotations/bookmarks without getting user’s approval.

They certainly don't modify files without saving/prompting. Plus, annotations and bookmarks don't happen automatically. A user has to do *something* to add a bookmark or annotation. Okular (most often used with KDE) will save annotations and bookmarks without prompting but it never modifies the original files.

ebook-viewer on the other hand modifies a file by just opening it and closing it.

I found this unexpected (to me) behaviour doing sanity checks on my file system. "WTH are these files changed? I've only viewed them…"

I can see how it's a useful feature but I think it really should be opt-in. Maybe there could be a one-time prompt when a book is first opened.