The manual overflow cull in HandleWorldMapPin compared icon:GetCenter()
against WorldMapScrollFrame's bounds without normalizing effective scale.
Magnify's zoom drags the icon's effective scale via WorldMapDetailFrame,
while the scroll frame's stays constant, so at high zoom ratios the
comparison failed for every icon and hid the whole map. Native
WorldMapScrollFrame:SetScrollChild() clipping (now reachable on all 4
edges since SetDrawOrder correctly detects bundled Magnify) already
handles this without the buggy manual math.
Narcasung
b4e0894c3f