[genesis] Allocation does not destroy the migrated timelock/gas coin when it is a "surplus"

[miker83z]

When the genesis is created through migration, the allocation process for timelocked or gas coins in favor of a list of validators includes a special "surplus" coin. This "surplus" coin is set aside during the transition from one validator's allocation to another's. Specifically, only a portion of its balance is used for a validator's allocation, while the remaining surplus may be utilized later for the next validator.

During this process, the last surplus timelocked coin picked during the execution of:

iota/crates/iota-genesis-builder/src/stake.rs

Line 349 in 3b51dac

fn pick_objects_for_allocation<'obj>(

will be put in the list of timelocks to split, here:

iota/crates/iota-genesis-builder/src/stake.rs

Line 273 in 3b51dac

self.timelocks_to_split

however, the original timelock object is never put in the list of objects to destroy

iota/crates/iota-genesis-builder/src/stake.rs

Line 204 in 3b51dac

self.timelocks_to_destroy

This basically results in cloning the object.

Suggested change:

• Put the newly selected surplus coin in the objects to destroy here:

  iota/crates/iota-genesis-builder/src/stake.rs

  Line 414 in 3b51dac

  // Do NOT place `obj_ref` in `to_destroy` because it is reused in the