[Bug 1569943] upgrading font version in a desktop session can affect rendering of text

https://bugzilla.redhat.com/show_bug.cgi?id=1569943

--- Comment #5 from Akira TAGOH  ---
This isn't an issue in fontconfig even. this would rather be an application
issue or rendering library where deal with file handles of fonts. fontconfig
provides an API to let them know if fonts are being updated. they have a way to
know that (but there are no way to know which one was updated...)
If they don't reopen a font when updating, the behavior may depends how they
open it. that is likely to see such issue anyway.