Papirus XApp Symbolic Icons

Papirus XApp Symbolic Icons is out: a drop-in set that gives the xsi-* icon names used by Linux Mint, Cinnamon, and the XApp projects proper Papirus artwork. Upstream draws its own Adwaita-derived versions and installs them into hicolor, so on a Papirus desktop every app asking for one of those names gets an icon that matches nothing around it. The set covers 628 of the 666 names, at 16, 22, and 24 pixels where upstream draws only 16, and installs into the Papirus theme so xsi-* lookups resolve there first. Nothing is hand-drawn: the whole set is generated from the Papirus and XSI sources, with no fuzzy matching anywhere.