Button Fixes:

Fix buttons not being able to be placed on ice.
Also, fix redstone circuits staying on if an activated button
was destroyed indirectly.

mods/ITEMS/REDSTONE/mesecons_button/init.lua

@@ -66,9 +66,11 @@ local function on_button_place(itemstack, placer, pointed_thing)
 		groups = def.groups
 	end
 
-	-- Only allow placement on full-cube solid opaque nodes
-	if (not groups) or (not groups.solid) or (not groups.opaque) or (def.node_box and def.node_box.type ~= "regular") then
-		return itemstack
+	-- Only allow placement on full-cube solid opaque nodes, and ice!
+	if (not groups) or (not groups.solid) or (def.node_box and def.node_box.type ~= "regular") or (not groups.ice) then
+		if (not groups.opaque) then
+			return itemstack
+		end
 	end
 
 	local above = pointed_thing.above
@@ -193,6 +195,10 @@ function mesecon.register_button(basename, description, texture, recipeitem, sou
 				mesecon.receptor_off(pos, button_get_output_rules(node))
 			end
 		end,
+		on_destruct = function(pos) -- Ensure redstone circuit turns off if button is destroyed
+			local node = minetest.get_node(pos)
+			mesecon.receptor_off(pos, button_get_output_rules(node))
+		end,
 
 		_mcl_blast_resistance = 0.5,
 		_mcl_hardness = 0.5,