Merge bitcoin/bitcoin#30272: doc: use TRUC instead of v3 and add release note

926b8e39dcbc0a3a8a75ef0a29bdca2bf738d746 [doc] add release note for TRUC (glozow)
19a9b90617419f68d0f1c90ee115b5220be99a16 use version=3 instead of v3 in debug strings (glozow)
881fac8e609be17eb71bd9a54c0284b304e2e2e2 scripted-diff: change names from V3 to TRUC (glozow)
a573dd261748d2a80560f73db08f7dca788c7fcf [doc] replace mentions of v3 with TRUC (glozow)
089b5757dff39a9a06cdb625aaced9beeb72958d rename mempool_accept_v3.py to mempool_truc.py (glozow)
f543852a89d93441645250c40c3980aeb0c3b664 rename policy/v3_policy.* to policy/truc_policy.* (glozow)

Pull request description:

  Adds a release note for TRUC policy which will be live in v28.0.

  For clarity, replaces mentions of "v3" with "TRUC" in most places. Suggested in
  - https://github.com/bitcoin/bitcoin/pull/29496#discussion_r1629749583
  - https://github.com/bitcoin/bitcoin/pull/29496#discussion_r1624500904

  I changed error strings from "v3-violation" to "TRUC-violation" but left v3 in the debug strings because I think it might be clearer for somebody who is debugging. Similarly, I left some variables unchanged because I think they're more descriptive this way, e.g. `tx_v3_from_v2_and_v3`. I'm happy to debate places that should or shouldn't be documented differently in this PR, whatever is clearest to everyone.

ACKs for top commit:
  instagibbs:
    reACK https://github.com/bitcoin/bitcoin/pull/30272/commits/926b8e39dcbc0a3a8a75ef0a29bdca2bf738d746
  achow101:
    ACK 926b8e39dcbc0a3a8a75ef0a29bdca2bf738d746
  ismaelsadeeq:
    Code review ACK 926b8e39dcbc0a3a8a75ef0a29bdca2bf738d746

Tree-SHA512: 16c88add0a29dc6d1236c4d45f34a17b850f6727b231953cbd52eb9f7268d1d802563eadfc8b7928c94ed3d7a615275dd103e57e81439ebf3ba2b12efa1e42af

1 files changed, 15 insertions, 15 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index 4241d51d15..7b586c45b8 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -35,7 +35,7 @@
 #include <policy/policy.h>
 #include <policy/rbf.h>
 #include <policy/settings.h>
-#include <policy/v3_policy.h>
+#include <policy/truc_policy.h>
 #include <pow.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
@@ -336,7 +336,7 @@ void Chainstate::MaybeUpdateMempoolForReorg(
     // Also updates valid entries' cached LockPoints if needed.
     // If false, the tx is still valid and its lockpoints are updated.
     // If true, the tx would be invalid in the next block; remove this entry and all of its descendants.
-    // Note that v3 rules are not applied here, so reorgs may cause violations of v3 inheritance or
+    // Note that TRUC rules are not applied here, so reorgs may cause violations of TRUC inheritance or
     // topology restrictions.
     const auto filter_final_and_mature = [&](CTxMemPool::txiter it)
         EXCLUSIVE_LOCKS_REQUIRED(m_mempool->cs, ::cs_main) {
@@ -829,7 +829,7 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
                 // check all unconfirmed ancestors; otherwise an opt-in ancestor
                 // might be replaced, causing removal of this descendant.
                 //
-                // All V3 transactions are considered replaceable.
+                // All TRUC transactions are considered replaceable.
                 //
                 // Replaceability signaling of the original transactions may be
                 // ignored due to node setting.
@@ -936,7 +936,7 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
     // while a tx could be package CPFP'd when entering the mempool, we do not have a DoS-resistant
     // method of ensuring the tx remains bumped. For example, the fee-bumping child could disappear
     // due to a replacement.
-    // The only exception is v3 transactions.
+    // The only exception is TRUC transactions.
     if (!bypass_limits && ws.m_ptx->version != TRUC_VERSION && ws.m_modified_fees < m_pool.m_opts.min_relay_feerate.GetFee(ws.m_vsize)) {
         // Even though this is a fee-related failure, this result is TX_MEMPOOL_POLICY, not
         // TX_RECONSIDERABLE, because it cannot be bypassed using package validation.
@@ -1005,7 +1005,7 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
         // If the new transaction is relatively small (up to 40k weight)
         // and has at most one ancestor (ie ancestor limit of 2, including
         // the new transaction), allow it if its parent has exactly the
-        // descendant limit descendants. The transaction also cannot be v3,
+        // descendant limit descendants. The transaction also cannot be TRUC,
         // as its topology restrictions do not allow a second child.
         //
         // This allows protocols which rely on distrusting counterparties
@@ -1032,7 +1032,7 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
     // Even though just checking direct mempool parents for inheritance would be sufficient, we
     // check using the full ancestor set here because it's more convenient to use what we have
     // already calculated.
-    if (const auto err{SingleV3Checks(ws.m_ptx, ws.m_ancestors, ws.m_conflicts, ws.m_vsize)}) {
+    if (const auto err{SingleTRUCChecks(ws.m_ptx, ws.m_ancestors, ws.m_conflicts, ws.m_vsize)}) {
         // Single transaction contexts only.
         if (args.m_allow_sibling_eviction && err->second != nullptr) {
             // We should only be considering where replacement is considered valid as well.
@@ -1043,15 +1043,15 @@ bool MemPoolAccept::PreChecks(ATMPArgs& args, Workspace& ws)
             ws.m_conflicts.insert(err->second->GetHash());
             // Adding the sibling to m_iters_conflicting here means that it doesn't count towards
             // RBF Carve Out above. This is correct, since removing to-be-replaced transactions from
-            // the descendant count is done separately in SingleV3Checks for v3 transactions.
+            // the descendant count is done separately in SingleTRUCChecks for TRUC transactions.
             ws.m_iters_conflicting.insert(m_pool.GetIter(err->second->GetHash()).value());
             ws.m_sibling_eviction = true;
             // The sibling will be treated as part of the to-be-replaced set in ReplacementChecks.
-            // Note that we are not checking whether it opts in to replaceability via BIP125 or v3
-            // (which is normally done in PreChecks). However, the only way a v3 transaction can
-            // have a non-v3 and non-BIP125 descendant is due to a reorg.
+            // Note that we are not checking whether it opts in to replaceability via BIP125 or TRUC
+            // (which is normally done in PreChecks). However, the only way a TRUC transaction can
+            // have a non-TRUC and non-BIP125 descendant is due to a reorg.
         } else {
-            return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "v3-rule-violation", err->first);
+            return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY, "TRUC-violation", err->first);
         }
     }
 
@@ -1103,7 +1103,7 @@ bool MemPoolAccept::ReplacementChecks(Workspace& ws)
     }
     // Enforce Rule #2.
     if (const auto err_string{HasNoNewUnconfirmed(tx, m_pool, m_subpackage.m_all_conflicts)}) {
-        // Sibling eviction is only done for v3 transactions, which cannot have multiple ancestors.
+        // Sibling eviction is only done for TRUC transactions, which cannot have multiple ancestors.
         Assume(!ws.m_sibling_eviction);
         return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
                              strprintf("replacement-adds-unconfirmed%s", ws.m_sibling_eviction ? " (including sibling eviction)" : ""), *err_string);
@@ -1545,10 +1545,10 @@ PackageMempoolAcceptResult MemPoolAccept::AcceptMultipleTransactions(const std::
     }
 
     // At this point we have all in-mempool ancestors, and we know every transaction's vsize.
-    // Run the v3 checks on the package.
+    // Run the TRUC checks on the package.
     for (Workspace& ws : workspaces) {
-        if (auto err{PackageV3Checks(ws.m_ptx, ws.m_vsize, txns, ws.m_ancestors)}) {
-            package_state.Invalid(PackageValidationResult::PCKG_POLICY, "v3-violation", err.value());
+        if (auto err{PackageTRUCChecks(ws.m_ptx, ws.m_vsize, txns, ws.m_ancestors)}) {
+            package_state.Invalid(PackageValidationResult::PCKG_POLICY, "TRUC-violation", err.value());
             return PackageMempoolAcceptResult(package_state, {});
         }
     }