From 72f0af48bc4bdeecf95153801dcb672cd7f4731c Mon Sep 17 00:00:00 2001
From: Ed Hennis <ed@ripple.com>
Date: Thu, 18 Aug 2022 13:09:14 -0700
Subject: [PATCH] fixup! Improve handling of 0 drop reference fee with TxQ

* Appropos of nothing, allow 0 reserves, too.
---
 src/ripple/app/misc/impl/TxQ.cpp | 18 +++++++++++++-----
 src/test/app/TxQ_test.cpp        |  6 +++---
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/ripple/app/misc/impl/TxQ.cpp b/src/ripple/app/misc/impl/TxQ.cpp
index f34427e46b1..8b56945c719 100644
--- a/src/ripple/app/misc/impl/TxQ.cpp
+++ b/src/ripple/app/misc/impl/TxQ.cpp
@@ -1078,19 +1078,27 @@ TxQ::apply(
                 LastLedgerSeq and MaybeTx::retriesRemaining.
             */
             auto const balance = (*sleAccount)[sfBalance].xrp();
-            /* Get the minimum possible reserve. If fees exceed
+            /* Get the minimum possible account reserve. If it
+               is at least 10 * the base fee, and fees exceed
                this amount, the transaction can't be queued.
-                Considering that typical fees are several orders
+
+               Currently typical fees are several orders
                of magnitude smaller than any current or expected
-               future reserve, this calculation is simpler than
+               future reserve. This calculation is simpler than
                trying to figure out the potential changes to
                the ownerCount that may occur to the account
-                as a result of these transactions, and removes
+               as a result of these transactions, and removes
                any need to account for other transactions that
                may affect the owner count while these are queued.
+
+               However, in case the account reserve is on a
+               comparable scale to the base fee, ignore the
+               reserve. Only check the account balance.
             */
             auto const reserve = view.fees().accountReserve(0);
-            if (totalFee >= balance || totalFee >= reserve)
+            auto const base = view.fees().base;
+            if (totalFee >= balance ||
+                (reserve > 10 * base && totalFee >= reserve))
             {
                 // Drop the current transaction
                 JLOG(j_.trace()) << "Ignoring transaction " << transactionID
diff --git a/src/test/app/TxQ_test.cpp b/src/test/app/TxQ_test.cpp
index 8b3ef686776..e25c9f60de1 100644
--- a/src/test/app/TxQ_test.cpp
+++ b/src/test/app/TxQ_test.cpp
@@ -4803,15 +4803,15 @@ class TxQ1_test : public beast::unit_test::suite
             makeConfig(
                 {{"minimum_txn_in_ledger_standalone", "3"}},
                 {{"reference_fee", "0"},
-                 {"account_reserve", "200"},
-                 {"owner_reserve", "50"}}));
+                 {"account_reserve", "0"},
+                 {"owner_reserve", "0"}}));
 
         BEAST_EXPECT(env.current()->fees().base == 10);
 
         checkMetrics(__LINE__, env, 0, std::nullopt, 0, 3, 256);
 
         // ledgers in queue is 2 because of makeConfig
-        auto const initQueueMax = initFee(env, 3, 2, 0, 200, 50);
+        auto const initQueueMax = initFee(env, 3, 2, 0, 0, 0);
 
         BEAST_EXPECT(env.current()->fees().base == 0);