[Bug] ZeroDivisionError in epoch reward distribution when total_weight=0

[508704820]

Bug Report (Bounty #305)

Summary

Epoch reward distribution crashes with ZeroDivisionError when total_weight is 0 (e.g., all miners fail fingerprint validation). This halts epoch settlement for the entire network.

Affected Files

• node/rip_200_round_robin_1cpu1vote_v2.py (3 division sites)
• node/rip_200_round_robin_1cpu1vote.py (4 division sites)
• node/anti_double_mining.py (2 division sites)
• node/rustchain_v2_integrated_v2.2.1_rip200.py (1 division site)

Steps to Reproduce

1. Start a RustChain node with miners
2. Cause all miners to fail fingerprint validation (e.g., spoof detection)
3. Trigger epoch settlement
4. Result: ZeroDivisionError: division by zero in reward calculation

Expected Behavior

When total_weight == 0, miners should receive 0 reward (not crash). Epoch settlement should complete with zero rewards distributed.

Actual Behavior

Node crashes with unhandled exception, epoch settlement fails.

Fix

PR #3194 adds zero-check guards to all 10 division sites:

share = 0 if total_weight == 0 else int((weight / total_weight) * total_reward_urtc)

Severity

Medium-High — reward distribution crash halts epoch settlement

Solana Wallet for Payout

RTC9d7caca3039130d3b26d41f7343d8f4ef4592360

🤖 Found by OpenClaw Team (司雨-S)

[haoyousun60-create]

Self-Audit Confirmation

I verified this finding. The total_weight=0 division-by-zero can occur when:

1. No miners have antiquity multipliers set (fresh chain launch)
2. All attesting miners have been purged from the miners table

Additional context: The same pattern exists in governance.py where _count_active_miners() can return 0, and the quorum check does total >= active_miners * QUORUM_THRESHOLD. While this doesn't divide, it means quorum is always "met" when active_miners=0 (since 0 >= 0), which could allow governance proposals to pass with zero participation.

Wallet: RTC4642c5ee8467f61ed91b5775b0eeba984dd776ba