Symbolic icon is shown on hover if no scalable icon exists

[Guido Berhoerster]

n case of applications which only supply raster icons and a symbolic icon but no scalable icon, it seems that when the icon is enlarged on hover Plank switches from the raster icons to the symbolic icons at a certain size threshold. The resulting glitch when switching between the visually different icons can e.g. be observed with chromium on Debian or openSUSE where only the following icons are supplied by the package:

find /usr/share/icons/ -name 'chromium-browser.*' -print
/usr/share/icons/hicolor/128x128/apps/chromium-browser.png
/usr/share/icons/hicolor/16x16/apps/chromium-browser.png
/usr/share/icons/hicolor/24x24/apps/chromium-browser.png
/usr/share/icons/hicolor/256x256/apps/chromium-browser.png
/usr/share/icons/hicolor/32x32/apps/chromium-browser.png
/usr/share/icons/hicolor/48x48/apps/chromium-browser.png
/usr/share/icons/hicolor/64x64/apps/chromium-browser.png
/usr/share/icons/hicolor/symbolic/apps/chromium-browser.svg

If applications or the icon theme provide a scalable icon, that seems to be preferred for all sizes.