Auto heirlooms causes autotrimps to hang when a (common) spire core is dropped

[5c00ter]

Console is filled with:
Uncaught TypeError: Cannot set property '1' of undefined
at worthOfHeirlooms (heirlooms.js:13)
at autoHeirlooms (heirlooms.js:141)
at mainLoop (AutoTrimps2.js:188)