test: add unit test coverage for the empty leaves path in MerkleComputation #33858

1. 
   frankomosh commented at 0:08 am on November 12, 2025: contributor

   As noted in #32243 (comment), the early return inside MerkleComputation when leaves.size() == 0 was only exercised by fuzz tests.

   The existing merkle_test_empty_block calls BlockMerkleRoot, which uses ComputeMerkleRoot, but does not exercise the TransactionMerklePath → ComputeMerklePath → MerkleComputation code path.

   Coverage before adding test:

   Coverage after adding test:

2. test: exercise TransactionMerklePath with empty block; targets the MerkleComputation empty-leaves path that was only reached by fuzz tests ffcae82a68
3. DrahtBot added the label Tests on Nov 12, 2025
4. 
   DrahtBot commented at 0:08 am on November 12, 2025: contributor

   The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

   Code Coverage & Benchmarks

   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/33858.

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   ACK	kevkevinpal

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5. 
   maflcko commented at 8:14 am on November 12, 2025: member

   Coverage before adding test:

   Coverage after adding test:

   I don’t think those links work. Also, this is redundant to the corecheck result anyway?

6. 
   frankomosh commented at 11:16 am on November 12, 2025: contributor

   I don’t think those links work.

   I’m not sure why they didn’t render correctly here. [Edit: I think it renders now]

   Also, this is redundant to the corecheck result anyway?

   I included them mainly to visually show % increase, but you’re right that they may be redundant. (also, I think you have been against adding tests without showing any proof of coverage)

7. 
   kevkevinpal commented at 3:07 pm on November 12, 2025: contributor

   ACK ffcae82

   According to corecheck it looks like there was an increase in coverage https://corecheck.dev/bitcoin/bitcoin/pulls/33858

Contributors
frankomosh DrahtBot maflcko kevkevinpal

Labels
Tests