Signal influence points: Make sure to clear on removal of signal, clear orphaned when digging rail

advtrains/signals.lua

@@ -9,6 +9,12 @@ local function can_dig_func(pos)
 	end
 	return true
 end
+local function after_dig_func(pos)
+	if advtrains.interlocking then
+		return advtrains.interlocking.signal_after_dig(pos)
+	end
+	return true
+end
 
 local function aspect(b)
 return {
@@ -97,6 +103,7 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 				supported_aspects = suppasp,
 			},
 			can_dig = can_dig_func,
+			after_dig_node = after_dig_func,
 		})
 		advtrains.trackplacer.add_worked("advtrains:retrosignal", r, rotation, nil)
 		
@@ -163,6 +170,7 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 				end,
 			},
 			can_dig = can_dig_func,
+			after_dig_node = after_dig_func,
 		})
 		advtrains.trackplacer.add_worked("advtrains:signal", r, rotation, nil)
 	end
@@ -232,6 +240,7 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 				end,
 			},
 			can_dig = can_dig_func,
+			after_dig_node = after_dig_func,
 		})
 	end
 end

advtrains/tracks.lua

@@ -622,7 +622,7 @@ function advtrains.can_dig_or_modify_track(pos)
 			return false, attrans("There's a Track Circuit Break here.")
 		end
 		-- signal ip?
-		if advtrains.interlocking.db.is_ip_at(pos) then
+		if advtrains.interlocking.db.is_ip_at(pos, true) then -- is_ip_at with purge parameter
 			return false, attrans("There's a Signal Influence Point here.")
 		end
 	end

advtrains_interlocking/database.lua

@@ -562,9 +562,23 @@ function ildb.set_sigd_for_signal(pos, sigd)
 end
 
 -- checks if there's any influence point set to this position
-function ildb.is_ip_at(pos)
+-- if purge is true, checks whether the associated signal still exists
+-- and deletes the ip if not.
+function ildb.is_ip_at(pos, purge)
 	local pts = advtrains.roundfloorpts(pos)
 	if influence_points[pts] then
+		if purge then
+			-- is there still a signal assigned to it?
+			for connid, sigpos in pairs(influence_points[pts]) do
+				local asp = advtrains.interlocking.signal_get_aspect(sigpos)
+				if not asp then
+					atlog("Clearing orphaned signal influence point", pts, "/", connid)
+					ildb.clear_ip_signal(pts, connid)
+				end
+			end
+			-- if there's no side left after purging, return false
+			if not influence_points[pts] then return false end
+		end
 		return true
 	end
 	return false

advtrains_interlocking/demosignals.lua

@@ -51,6 +51,7 @@ minetest.register_node("advtrains_interlocking:ds_danger", {
 	},
 	on_rightclick = advtrains.interlocking.signal_rc_handler,
 	can_dig = advtrains.interlocking.signal_can_dig,
+	after_dig_node = advtrains.interlocking.signal_after_dig,
 })
 minetest.register_node("advtrains_interlocking:ds_free", {
 	description = "Demo signal at Free",
@@ -72,6 +73,7 @@ minetest.register_node("advtrains_interlocking:ds_free", {
 	},
 	on_rightclick = advtrains.interlocking.signal_rc_handler,
 	can_dig = advtrains.interlocking.signal_can_dig,
+	after_dig_node = advtrains.interlocking.signal_after_dig,
 })
 minetest.register_node("advtrains_interlocking:ds_slow", {
 	description = "Demo signal at Slow",
@@ -93,5 +95,6 @@ minetest.register_node("advtrains_interlocking:ds_slow", {
 	},
 	on_rightclick = advtrains.interlocking.signal_rc_handler,
 	can_dig = advtrains.interlocking.signal_can_dig,
+	after_dig_node = advtrains.interlocking.signal_after_dig,
 })
 

advtrains_signals_ks/init.lua

@@ -115,6 +115,7 @@ for _, rtab in ipairs({
 			},
 			on_rightclick = advtrains.interlocking.signal_rc_handler,
 			can_dig = advtrains.interlocking.signal_can_dig,
+			after_dig_node = advtrains.interlocking.signal_after_dig,
 		})
 		-- rotatable by trackworker
 		advtrains.trackplacer.add_worked("advtrains_signals_ks:hs", typ, "_"..rot, prts.n)
@@ -160,6 +161,7 @@ for _, rtab in ipairs({
 			},
 			on_rightclick = advtrains.interlocking.signal_rc_handler,
 			can_dig = advtrains.interlocking.signal_can_dig,
+			after_dig_node = advtrains.interlocking.signal_after_dig,
 		})
 		-- rotatable by trackworker
 		advtrains.trackplacer.add_worked("advtrains_signals_ks:ra", typ, "_"..rot, prts.n)
@@ -210,6 +212,7 @@ for _, rtab in ipairs({
 			},
 			on_rightclick = advtrains.interlocking.signal_rc_handler,
 			can_dig = advtrains.interlocking.signal_can_dig,
+			after_dig_node = advtrains.interlocking.signal_after_dig,
 		})
 		-- rotatable by trackworker
 		advtrains.trackplacer.add_worked("advtrains_signals_ks:sign", typ, "_"..rot, prts.n)