glib: keep same visual appearance between displayed and copied text
When copying text from displayed document to the clipboard, we want a normalization that preserves 'canonical equivalence' i.e. that the text after normalization is not visually different than the original text. Our previous normalization was just preserving unicode 'compatibility'.
Relevant documentation:
- https://www.win.tue.nl/~aeb/linux/uc/nfc_vs_nfd.html
- https://en.wikipedia.org/wiki/Unicode_equivalence
- https://developer.gnome.org/glib/stable/glib-Unicode-Manipulation.html#g-utf8-normalize
Issue #724 (closed)