News317: add notable code changes

Author: Gustavojfe

_posts/en/newsletters/2024-08-23-newsletter.md

@@ -141,30 +141,91 @@ Proposals (BIPs)][bips repo], [Lightning BOLTs][bolts repo],
 [Lightning BLIPs][blips repo], [Bitcoin Inquisition][bitcoin inquisition
 repo], and [BINANAs][binana repo]._
 
-- [Bitcoin Core #28553][] validation: assumeutxo params mainnet
-
-- [Bitcoin Core #30246][] contrib: asmap-tool - Compare ASMaps with respect to specific addresses
-
-- [Bitcoin Core GUI #824][] Migrate legacy wallets that are not loaded
-
-- [Core Lightning #7540][] renepay: add const probability cost
-
-- [Core Lightning #7403][] renepay: add a channel filtering paymod
-
-- [LND #8943][] Roasbeef/alloy-linear-fee-model <!-- mainly looking for a mention of Alloy and how it could be useful to other Bitcoin projects; probably only need a short mention of the fee function bug fix -->
-
-- [BDK #1478][] Allow opting out of getting `LocalChain` updates with `FullScanRequest`/`SyncRequest` structures
-
-- [BDK #1533][] Enable support for single descriptor wallets
-
-- [BOLTs #1182][] BOLT 4: clarify blinded path requirements.
-
-- [BLIPs #39][] blip-0039: BOLT 11 Invoice Blinded Path Tagged Field
+- [Bitcoin Core #28553][] adds [assumeUTXO][topic assumeutxo] snapshot
+  parameters for mainnet block 840,000: its block hash, the number of
+  transactions up to that block, and the SHA256 hash of the serialized UTXO set
+  up to that block. This follows tests by multiple contributors that they can
+  reproduce the same [snapshot file][] with the expected SHA256 checksum, and that
+  the snapshot works well when loaded.
+
+- [Bitcoin Core #30246][] introduces a `diff_addrs` subcommand to the
+  `asmap-tool` utility to allow users to compare two maps of [Autonomous
+  Systems][auto sys] (ASMaps) and compute statistics on how many node network
+  addresses have been reassigned to a different Autonomous System Number (ASN).
+  This functionality quantifies the degradation of an ASMap over time, which is
+  an important step towards eventually shipping precomputed ASMaps in Bitcoin
+  Core releases, and further increase Bitcoin Core’s resistance to [eclipse
+  attacks][topic eclipse attacks]. See Newsletter [#290][news290 asmap].
+
+- [Bitcoin Core GUI #824][] changes the `Migrate Wallet` menu item from a single
+  action to a menu list, allowing users to migrate any legacy wallet in the
+  wallet directory, including unloadable wallets. This change prepares for a
+  possible future where legacy wallets may no longer be loadable in Bitcoin
+  Core, with [descriptor][topic descriptors] wallets becoming the default. When
+  selecting a wallet to migrate, the GUI will prompt the user to enter the
+  wallet’s passphrase, if it has one.
+
+- [Core Lightning #7540][] improves the formula that calculates the probability
+  of a successful routing through a channel in the `renepay` plugin (see
+  Newsletter [#263][news263 renepay]) by adding a constant multiplier that
+  represents the probability that a randomly chosen channel in the network is
+  able to forward at least 1 msat. The default value is set to 0.98, but this
+  may be changed in the future after further testing.
+
+- [Core Lightning #7403][] adds a channel filtering payment modifier to the
+  `renepay` plugin which disables channels with a very low `max_htlc`. This can
+  be extended in the future to filter out channels that are undesirable for
+  other reasons: high base fee, low capacity, and high latency. In addition, a new
+  `exclude` command line option has been added to manually disable nodes or channels.
+
+- [LND #8943][] introduces [Alloy][alloy model] models to the codebase, starting
+  with an initial Alloy model for the [Linear Fee Function][lnd linear] fee
+  bumping mechanism, inspired by a bugfix [LND #8751][]. Alloy provides a
+  lightweight formal method for verifying the correctness of system components
+  to make it easier to find bugs during the initial implementation. Rather than
+  trying to prove that a model is always correct, as full-blown formal methods
+  do, Alloy instead operates on an input of a set of bounded parameters and
+  iterations and tries to find counterexamples to a given assertion, accompanied
+  by a nice visualizer. Models can also be used to specify protocols in P2P
+  systems, so it's particularly well suited to the Lightning Network.
+
+- [BDK #1478][] makes several changes to the `FullScanRequest` and `SyncRequest`
+  request structures of the `bdk_chain` crate: use a builder pattern that
+  separates request construction and consumption, make the `chain_tip` parameter
+  optional to allow users to opt out of `LocalChain` updates (useful for those
+  using `bdk_esplora` without a `LocalChain`), and improve the ergonomics of
+  checking synchronization progress. In addition, the `bdk_esplora` crate is
+  optimized by always adding previous transaction outputs  to the `TxGraph`
+  update and reducing the number of API calls by using the `/tx/:txid` endpoint.
+
+- [BDK #1533][] enables support for single [descriptor][topic descriptors]
+  wallets by adding the `Wallet::create_single` method, reverting a previous
+  update that had made the `Wallet` structure require an internal (change)
+  descriptor. The reason for the previous change was to protect the privacy of
+  users' change addresses when relying on public Electrum or Esplora servers,
+  but this is being reverted to be inclusive of all use cases.
+
+- [BOLTs #1182][] improves the clarity and completeness of the [route
+  blinding][topic rv routing] and [onion messages][topic onion messages]
+  sections of the [BOLT4][] specification with the following changes: moves the
+  route blinding section up one level to emphasize its applicability to payments
+  (and not just onion messages), provides more concrete details on the
+  `blinded_path` type and its requirements, expands the description of the
+  writer's responsibilities, splits the reader section into separate parts for
+  the `blinded_path` and `encrypted_recipient_data`, improves the explanation of
+  the `blinded_path` concept, adds a recommendation to use a dummy hop, renames
+  `onionmsg_hop` to `blinded_path_hop`, and makes other clarifying changes.
+
+- [BLIPs #39][] adds [BLIP39][] for an optional field `b` in [BOLT11][] invoices to
+  communicate a [blinded path][topic rv routing] for paying the receiver’s node.
+  This is implemented in LND (see Newsletter [#315][news315 blinded]) and is
+  intended to be used until the [offers][topic offers] protocol is widely
+  deployed in the network.
 
 {% assign four_days_after_posting = page.date | date: "%s" | plus: 345600 | date: "%Y-%m-%d 14:30" %}
 {% include snippets/recap-ad.md when=four_days_after_posting %}
 {% include references.md %}
-{% include linkers/issues.md v=2 issues="28553,30246,824,7540,7403,8943,1478,1533,1182,39" %}
+{% include linkers/issues.md v=2 issues="28553,30246,824,7540,7403,8943,1478,1533,1182,39,8751" %}
 [Core Lightning 24.08rc2]: https://github.com/ElementsProject/lightning/releases/tag/v24.08rc2
 [LND v0.18.3-beta.rc1]: https://github.com/lightningnetwork/lnd/releases/tag/v0.18.3-beta.rc1
 [moonsettler exfil1]: https://delvingbitcoin.org/t/non-interactive-anti-exfil-airgap-compatible/1081
@@ -189,3 +250,10 @@ repo], and [BINANAs][binana repo]._
 [seedsigner 0.8.0]: https://github.com/SeedSigner/seedsigner/releases/tag/0.8.0
 [floresta 0.6.0]: https://github.com/vinteumorg/Floresta/releases/tag/0.6.0
 [floresta blog]: https://medium.com/vinteum-org/floresta-update-simplifying-bitcoin-node-integration-for-wallets-6886ea7c975c
+[auto sys]: https://en.wikipedia.org/wiki/Autonomous_system_(Internet)
+[news290 asmap]: /en/newsletters/2024/02/21/#improved-reproducible-asmap-creation-process
+[news263 renepay]: /en/newsletters/2023/08/09/#core-lightning-6376
+[alloy model]: https://alloytools.org/about.html
+[lnd linear]: https://github.com/lightningnetwork/lnd/blob/b7c59b36a74975c4e710a02ea42959053735402e/sweep/fee_function.go#L66-L109
+[news315 blinded]: /en/newsletters/2024/08/09/#lnd-8735
+[snapshot file]: magnet:?xt=urn:btih:596c26cc709e213fdfec997183ff67067241440c&dn=utxo-840000.dat&tr=udp%3A%2F%2Ftracker.bitcoin.sprovoost.nl%3A6969

_topics/en/assumeutxo.md

@@ -67,6 +67,9 @@ optech_mentions:
   - title: "Bitcoin Core #30598 removes block height from the assumeUTXO snapshot file metadata"
     url: /en/newsletters/2024/08/16/#bitcoin-core-30598
 
+  - title: "Bitcoin Core #28553 adds assumeUTXO snapshot parameters for mainnet block 840,000"
+    url: /en/newsletters/2024/08/23/#bitcoin-core-28553
+
 ## Optional.  Same format as "primary_sources" above
 see_also:
   - title: "Bitcoin Core issue #15605: AssumeUTXO discussion"

_topics/en/pay-to-contract-outputs.md

@@ -39,6 +39,9 @@ optech_mentions:
   - title: "PSBT extension for pay-to-contract fields"
     url: /en/newsletters/2022/01/26/#psbt-extension-for-p2c-fields
 
+  - title: "BIPs #1293 adds BIP372 Pay-to-contract tweak fields for PSBT"
+    url: /en/newsletters/2022/10/05/#bips-1293
+
 ## Optional.  Same format as "primary_sources" above
 see_also:
   - title: Proof of payment

_topics/en/rendez-vous-routing.md

@@ -98,6 +98,9 @@ optech_mentions:
   - title: "LND #8735 and #8764 improve LND's support for blinded paths, including for multipath"
     url: /en/newsletters/2024/08/09/#lnd-8735
 
+  - title: "BLIPs #39 adds BLIP39 for an optional field b in BOLT11 invoices to communicate a blinded path"
+    url: /en/newsletters/2024/08/23/#blips-39
+
 ## Optional.  Same format as "primary_sources" above
 see_also:
   - title: Unannounced channels