Add a vector that would have caught https://github.com/bitcoin/bitcoin/pull/36076.
Additionally, #2075 clarified that Combine is not commutative, however the actual test vectors are. The first commit clarifies that the existing test vectors should be run in both orders, while leaving room for exceptions if we ever need to standardize conflict resolution.
The Combiner section is updated to say combining is commutative unless
the PSBTs have conflicting fields. None of the current combiner test
vectors contain such fields.
Concept ACK. @achow101?
838 | @@ -839,6 +839,12 @@ A combiner which orders keys lexicographically must produce the following PSBT: 839 | * Bytes in Hex: <pre>70736274ff01003f0200000001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000000000ffffffff010000000000000000036a0100000000000af00102030405060708090f0102030405060708090a0b0c0d0e0f0af00102030405060708100f0102030405060708090a0b0c0d0e0f000af00102030405060708090f0102030405060708090a0b0c0d0e0f0af00102030405060708100f0102030405060708090a0b0c0d0e0f000af00102030405060708090f0102030405060708090a0b0c0d0e0f0af00102030405060708100f0102030405060708090a0b0c0d0e0f00</pre> 840 | * Base64 String: <pre>cHNidP8BAD8CAAAAAf//////////////////////////////////////////AAAAAAD/////AQAAAAAAAAAAA2oBAAAAAAAK8AECAwQFBgcICQ8BAgMEBQYHCAkKCwwNDg8K8AECAwQFBgcIEA8BAgMEBQYHCAkKCwwNDg8ACvABAgMEBQYHCAkPAQIDBAUGBwgJCgsMDQ4PCvABAgMEBQYHCBAPAQIDBAUGBwgJCgsMDQ4PAArwAQIDBAUGBwgJDwECAwQFBgcICQoLDA0ODwrwAQIDBAUGBwgQDwECAwQFBgcICQoLDA0ODwA=</pre> 841 | 842 | +Given the updated PSBT from above (before SIGHASH_ALL was added to it) and this PSBT, created from it by a signer with the keys <tt>cP53pDbR5WtAD8dYAW9hhTjuvvTVaEiQBdrz9XPrgLBeRFiyCbQr</tt> (<tt>m/0'/0'/0'</tt>) and <tt>cR6SXDoyfQrcp4piaiHE97Rsgta9mNhGTen9XeonVgwsh4iSgw6d</tt> (<tt>m/0'/0'/2'</tt>) which signs with SIGHASH_ALL|SIGHASH_ANYONECANPAY and records that in <tt>PSBT_IN_SIGHASH_TYPE</tt>:
The description does not need that much detail. The signer and which keys were used are not relevant for this test.
Add a vector where only one of the two PSBTs has the
PSBT_IN_SIGHASH_TYPE field.
See bitcoin/bitcoin#36076
838 | @@ -839,6 +839,12 @@ A combiner which orders keys lexicographically must produce the following PSBT: 839 | * Bytes in Hex: <pre>70736274ff01003f0200000001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000000000ffffffff010000000000000000036a0100000000000af00102030405060708090f0102030405060708090a0b0c0d0e0f0af00102030405060708100f0102030405060708090a0b0c0d0e0f000af00102030405060708090f0102030405060708090a0b0c0d0e0f0af00102030405060708100f0102030405060708090a0b0c0d0e0f000af00102030405060708090f0102030405060708090a0b0c0d0e0f0af00102030405060708100f0102030405060708090a0b0c0d0e0f00</pre> 840 | * Base64 String: <pre>cHNidP8BAD8CAAAAAf//////////////////////////////////////////AAAAAAD/////AQAAAAAAAAAAA2oBAAAAAAAK8AECAwQFBgcICQ8BAgMEBQYHCAkKCwwNDg8K8AECAwQFBgcIEA8BAgMEBQYHCAkKCwwNDg8ACvABAgMEBQYHCAkPAQIDBAUGBwgJCgsMDQ4PCvABAgMEBQYHCBAPAQIDBAUGBwgJCgsMDQ4PAArwAQIDBAUGBwgJDwECAwQFBgcICQoLDA0ODwrwAQIDBAUGBwgQDwECAwQFBgcICQoLDA0ODwA=</pre> 841 | 842 | +Given the updated PSBT from above (before SIGHASH_ALL was added to it) and this PSBT, created from it by a signer with the keys <tt>cP53pDbR5WtAD8dYAW9hhTjuvvTVaEiQBdrz9XPrgLBeRFiyCbQr</tt> (<tt>m/0'/0'/0'</tt>) and <tt>cR6SXDoyfQrcp4piaiHE97Rsgta9mNhGTen9XeonVgwsh4iSgw6d</tt> (<tt>m/0'/0'/2'</tt>) which signs with SIGHASH_ALL|SIGHASH_ANYONECANPAY and records that in <tt>PSBT_IN_SIGHASH_TYPE</tt>: 843 | +* Bytes in Hex: <pre>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</pre> 844 | +** Base64 String: <pre>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</pre> 845 | + 846 | +A combiner must produce a PSBT identical to the signer's PSBT. <tt>PSBT_IN_SIGHASH_TYPE</tt> is only present in one of the two PSBTs and must be retained.
This description about the behavior is unnecessary. Just give the PSBT that is supposed to be produced, do not just say "the signer's PSBT", this is ambiguous.
Trimmed the text and just copy-pasted both PSBTs, instead of trying to point to them (the vectors are not numbered or named).