fix nil reference crash in tube autorouter when unknown nodes are nearby

(?)

diff --git a/autoplace_tubes.lua b/autoplace_tubes.lua
index 441e62a0d990d5b1b34db2e5c988f25c3ff39db9..385458c7de94a934b5e5cf698dee8ebddec1caf5 100644 (file)
--- a/autoplace_tubes.lua
+++ b/autoplace_tubes.lua
@@ -100,7 +100,7 @@ local function tube_autoroute(pos)
                if is_tube(node.name) then
                        active[i] = 1
                -- handle new style connectors
-               elseif idef.tube and idef.tube.connect_sides then
+               elseif idef and idef.tube and idef.tube.connect_sides then
                        local dir = adjustments[i]
                        if idef.tube.connect_sides[nodeside(node, {x=-dir.x, y=-dir.y, z=-dir.z})] then active[i] = 1 end
                end