fix(rpc): Missing boundary check in GetTransactionReceipt

[JayT106]

Closes: #XXX

Description

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[codecov]

Codecov Report

❌ Patch coverage is 21.87500% with 25 lines in your changes missing coverage. Please review.
✅ Project coverage is 40.66%. Comparing base (a55a578) to head (47170d8).

Files with missing lines	Patch %	Lines
rpc/backend/tx_info.go	21.87%	17 Missing and 8 partials ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #861      +/-   ##
===========================================
- Coverage    40.69%   40.66%   -0.04%     
===========================================
  Files          190      190              
  Lines        15452    15471      +19     
===========================================
+ Hits          6288     6291       +3     
- Misses        8491     8499       +8     
- Partials       673      681       +8     

Files with missing lines	Coverage Δ
rpc/backend/tx_info.go	54.19% <21.87%> (-2.51%)	⬇️

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[songgaoye]

I think we should also check other code in tx_info.go like GetTransactionByHash and GetTransactionByBlockAndIndex, they use tx.GetMsgs()[res.MsgIndex] and block.Block.Txs[res.TxIndex] in similar ways.

[thomas-nguy]

Do you know in which scenario this is possible?

[JayT106]

Theoretically it shouldn't happen. It just a defensive coding.

[JayT106]

I think we should also check other code in tx_info.go like GetTransactionByHash and GetTransactionByBlockAndIndex, they use tx.GetMsgs()[res.MsgIndex] and block.Block.Txs[res.TxIndex] in similar ways.

check added.

[songgaoye]

lgtm