fix: remove double conversion in stake swap functionality [--swap_all]

[ashikshafi08]

Fix Double Conversion Bug in Stake Swap Functionality

Issue Description

A bug was discovered in the stake swap functionality when using the --swap-all flag. The bug caused massive stake amount inflation due to an unnecessary double conversion of the Balance object.

Problem Details

• When using --swap-all, the code was incorrectly converting an already-converted Balance object
• This resulted in massive stake amount inflation
• Example:
  • Input stake amount: 21.5369 פ
  • Incorrectly inflated amount: 21,536,911,597.0000 פ

Root Cause

The bug occurred in move.py where:

# Buggy code
if swap_all:
    amount_to_swap = Balance.from_tao(current_stake).set_unit(origin_netuid)

The current_stake was already a Balance object, but Balance.from_tao() was being called on it again, causing double conversion.

Solution

Fixed by removing the unnecessary Balance.from_tao() conversion:

# Fixed code
if swap_all:
    amount_to_swap = current_stake.set_unit(origin_netuid)

This change ensures the Balance object is only converted once, maintaining the correct stake amount.

Testing Performed

• Tested with real wallet and subnet data
• Verified correct stake conversion amounts
• Tested cross-subnet stake swap functionality
• Confirmed no multiplication of amounts occurs
• Example test case:
  • Wallet: coldkey_1
  • Hotkey: hot_25
  • Origin Subnet: 45 (21.5369 פ)
  • Destination Subnet: 0
  • Result: Correct conversion to 0.7464 τ

Impact

This fix prevents potential significant financial losses that could occur due to incorrect stake amount calculations when using the --swap-all flag.

[thewhaleking]

Great catch!