From 0f33cb2fdd385b92a2acb70ca983f2d12feabd13 Mon Sep 17 00:00:00 2001
From: xdustinface <xdustinfacex@gmail.com>
Date: Thu, 18 Dec 2025 14:46:06 +1100
Subject: [PATCH 1/2] Improve `test_gap_limit_maintenance`

---
 .../src/managed_account/address_pool.rs       | 45 ++++++++++++++-----
 1 file changed, 34 insertions(+), 11 deletions(-)

diff --git a/key-wallet/src/managed_account/address_pool.rs b/key-wallet/src/managed_account/address_pool.rs
index 50100d3be..683ce2493 100644
--- a/key-wallet/src/managed_account/address_pool.rs
+++ b/key-wallet/src/managed_account/address_pool.rs
@@ -1229,21 +1229,44 @@ mod tests {
     #[test]
     fn test_gap_limit_maintenance() {
         let base_path = DerivationPath::from(vec![ChildNumber::from_normal_idx(0).unwrap()]);
-        let mut pool = AddressPool::new_without_generation(
-            base_path,
-            AddressPoolType::External,
-            5,
-            Network::Testnet,
-        );
         let key_source = test_key_source();
+        let gap_limit = 5;
+
+        // Create pool with gap_limit addresses already generated
+        let mut pool =
+            AddressPool::new(base_path, AddressPoolType::External, gap_limit, Network::Testnet, &key_source)
+                .unwrap();
+
+        // Verify gap_limit addresses generated, none used
+        assert_eq!(pool.highest_generated, Some(gap_limit - 1));
+        assert_eq!(pool.highest_used, None);
+        assert_eq!(pool.addresses.len(), gap_limit as usize);
+
+        // Calling maintain_gap_limit should not generate any new addresses when none are used
+        let new_addresses = pool.maintain_gap_limit(&key_source).unwrap();
+        assert_eq!(new_addresses.len(), 0);
+        assert_eq!(pool.highest_generated, Some(gap_limit - 1));
+        assert_eq!(pool.addresses.len(), gap_limit as usize);
+
+        // Mark address at index 0 as used
+        pool.mark_index_used(0);
+        assert_eq!(pool.highest_used, Some(0));
+
+        // Should generate exactly 1 address to maintain gap_limit unused after index 0
+        let new_addresses = pool.maintain_gap_limit(&key_source).unwrap();
+        assert_eq!(new_addresses.len(), 1);
+        assert_eq!(pool.highest_generated, Some(gap_limit));
+        assert_eq!(pool.addresses.len(), gap_limit as usize + 1);
 
-        // Generate initial addresses
-        pool.generate_addresses(3, &key_source, true).unwrap();
+        // Mark address at index 1 and 2 as used
         pool.mark_index_used(1);
+        pool.mark_index_used(2);
 
-        // Maintain gap limit
-        let _new_addrs = pool.maintain_gap_limit(&key_source).unwrap();
-        assert!(pool.highest_generated.unwrap_or(0) >= 6); // Should have at least index 1 + gap limit 5
+        // Should generate exactly 2 more addresses
+        let new_addresses = pool.maintain_gap_limit(&key_source).unwrap();
+        assert_eq!(new_addresses.len(), 2);
+        assert_eq!(pool.highest_generated, Some(gap_limit + 2));
+        assert_eq!(pool.addresses.len(), gap_limit as usize + 3);
     }
 
     #[test]

From caf9231cfc71f35388712041ff45b527090a6f90 Mon Sep 17 00:00:00 2001
From: xdustinface <xdustinfacex@gmail.com>
Date: Thu, 18 Dec 2025 14:40:28 +1100
Subject: [PATCH 2/2] fix: `maintain_gap_limit` target calculation off by one

The target index was calculated incorrectly, causing one extra address to be generated.

See the test added which fails without the fix.
---
 key-wallet/src/managed_account/address_pool.rs | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/key-wallet/src/managed_account/address_pool.rs b/key-wallet/src/managed_account/address_pool.rs
index 683ce2493..a4709bd74 100644
--- a/key-wallet/src/managed_account/address_pool.rs
+++ b/key-wallet/src/managed_account/address_pool.rs
@@ -885,8 +885,8 @@ impl AddressPool {
     /// Generate addresses to maintain the gap limit
     pub fn maintain_gap_limit(&mut self, key_source: &KeySource) -> Result<Vec<Address>> {
         let target = match self.highest_used {
-            None => self.gap_limit,
-            Some(highest) => highest + self.gap_limit + 1,
+            None => self.gap_limit - 1,
+            Some(highest) => highest + self.gap_limit,
         };
 
         let mut new_addresses = Vec::new();
@@ -1233,9 +1233,14 @@ mod tests {
         let gap_limit = 5;
 
         // Create pool with gap_limit addresses already generated
-        let mut pool =
-            AddressPool::new(base_path, AddressPoolType::External, gap_limit, Network::Testnet, &key_source)
-                .unwrap();
+        let mut pool = AddressPool::new(
+            base_path,
+            AddressPoolType::External,
+            gap_limit,
+            Network::Testnet,
+            &key_source,
+        )
+        .unwrap();
 
         // Verify gap_limit addresses generated, none used
         assert_eq!(pool.highest_generated, Some(gap_limit - 1));