In the past, when I saved a document and hadn't yet made additional changes, the "save" button was grayed out. This let me know that I had done the save and avoided doing so redundantly. With the most recent versions (I have 5.1.5.2-3 for Fedora 24), that doesn't seem to be true any more. Why not? Can this be fixed? If it matters, I use text buttons, not icons.
Duplicate of bug 98779, but also see steps for alternative from patch for bug 98745#c20 for 5.2 releases. *** This bug has been marked as a duplicate of bug 98779 ***