Chore(scripts): Add script to check kernel commits in subtree updates

[alexanderwiederin]

Changes

Adds a script that logs the kernel related changes in the last subtree merge.

Example:

Finding latest subtree merge for libbitcoinkernel-sys/bitcoin...
Checking merge commit 7334556a...

=== Subtree Merge Information ===
Merge commit: 7334556a3fabc65f749269e1462fb617f5d414a6
Merge date: 2025-12-01 13:58:46 +0100
Previous upstream: 3789215f
New upstream: 6356041e
Range: 3789215f..6356041e

GitHub Compare:
https://github.com/bitcoin/bitcoin/compare/3789215f7346...6356041e58d1

Found        2 commit(s) with 'kernel:' prefix

Commit: 6657bcbdb4d0
Message: kernel: allow null data_directory

An empty path may be represented with a nullptr. For example,
std::string_view::data() may return nullptr.

Removes the BITCOINKERNEL_ARG_NONNULL attribute for data_directory,
and instead handles such null arguments in the implementation.

Also documents how BITCOINKERNEL_ARG_NONNULL should be used.
Author: stickies-v
Date: 2025-11-12
Files changed:
  src/kernel/bitcoinkernel.cpp
  src/kernel/bitcoinkernel.h
  src/kernel/bitcoinkernel_wrapper.h
  src/test/kernel/test_kernel.cpp

---

Commit: 096924d39d64
Message: kernel: add btck_block_tree_entry_equals

BlockTreeEntry objects are often compared. By exposing an equality
function, clients don't have to implement more expensive
comparisons based on height and block hash.
Author: stickies-v
Date: 2025-11-11
Files changed:
  src/kernel/bitcoinkernel.cpp
  src/kernel/bitcoinkernel.h
  src/kernel/bitcoinkernel_wrapper.h
  src/test/kernel/test_kernel.cpp

---


Total:        2 kernel-related commit(s)

[sedited]

Can you put this into a new directory called contrib? And I think it would be good to commit it with executable permissions, maybe run chomd +x check_subtree_kernel_commits.sh?

[alexanderwiederin]

Done - thanks! Next to your suggestions, I also made a slight change to a comment in the script file.

# Try to get previous upstream from the merge -> # Extract the previous upstream commit from the merge

[sedited]

lgtm