test: clarify submitBlock() mutates the template
What the developer wrote
Authored by Sjors Provoost
test: clarify submitBlock() mutates the template
PR #33374 proposed a new Mining IPC method applySolution() which
could be used by clients to obtain the reconstructed block for
inspection, especially in the case of a rejected block.
However it was pointed out during review that submitBlock() modified
the template CBlock in place, so the client can just call getBlock()
and no new method is needed.
This commit adds a test to document that (now intentional) behavior.
What changed, and why it matters
This is a harmless test-only change. It adds a new test case to make sure developers know that a mining interface function called submitBlock() changes the block template even when the submitted block is rejected. There is no security fix or vulnerability here.
No action needed. This is a test-only documentation commit with no security relevance.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The commit adds assertions in test/functional/interface_ipc.py documenting that submitBlock()/submitSolution() mutates the remote CBlock template in place, including on a rejected submission. It verifies the mutation by comparing serialized versions of the parsed template before and after a rejected call. This is purely a behavioral regression test; no production code is modified.
Changed components
test/functional/interface_ipc.pyInspect captured patch +9 / −0
diff --git a/test/functional/interface_ipc.py b/test/functional/interface_ipc.py
index e905c775..cce56e32 100755
--- a/test/functional/interface_ipc.py
+++ b/test/functional/interface_ipc.py
@@ -215,11 +215,20 @@ class IPCInterfaceTest(BitcoinTestFramework):
res = await mining.result.checkBlock(block.serialize(), check_opts)
assert_equal(res.result, True)
+ # The remote template block will be mutated, capture the original:
+ remote_block_before = await self.parse_and_deserialize_block(template, ctx)
+
self.log.debug("Submitted coinbase must include witness")
assert_not_equal(coinbase.serialize_without_witness().hex(), coinbase.serialize().hex())
res = await template.result.submitSolution(ctx, block.nVersion, block.nTime, block.nNonce, coinbase.serialize_without_witness())
assert_equal(res.result, False)
+ self.log.debug("Even a rejected submitBlock() mutates the template's block")
+ # Can be used by clients to download and inspect the (rejected)
+ # reconstructed block.
+ remote_block_after = await self.parse_and_deserialize_block(template, ctx)
+ assert_not_equal(remote_block_before.serialize().hex(), remote_block_after.serialize().hex())
+
self.log.debug("Submit again, with the witness")
res = await template.result.submitSolution(ctx, block.nVersion, block.nTime, block.nNonce, coinbase.serialize())
assert_equal(res.result, True)
Why this scored 15/100
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