Add min_childkey_take_per_subnet hyperparameter

pallets/subtensor/src/swap/swap_hotkey.rs

@@ -46,17 +46,20 @@ impl<T: Config> Pallet<T> {
             Error::<T>::NonAssociatedColdKey
         );
 
-        // 3. If the new hotkey already exists globally, ensure the coldkey owns it
+        // 3. Initialize the weight for this operation. The coldkey/old_hotkey
+        // ownership check above reads Owner twice.
+        let mut weight = T::DbWeight::get().reads(2);
+
+        // 4. If the new hotkey already exists globally, ensure the coldkey owns it
+        weight.saturating_accrue(T::DbWeight::get().reads(1));
         if Self::hotkey_account_exists(new_hotkey) {
+            weight.saturating_accrue(T::DbWeight::get().reads(2));
             ensure!(
                 Self::coldkey_owns_hotkey(&coldkey, new_hotkey),
                 Error::<T>::NonAssociatedColdKey
             );
         }
 
-        // 4. Initialize the weight for this operation
-        let mut weight = T::DbWeight::get().reads(2);
-
         // 5. Ensure the new hotkey is different from the old one
         ensure!(old_hotkey != new_hotkey, Error::<T>::NewHotKeyIsSameWithOld);
 

pallets/subtensor/src/tests/swap_hotkey_with_subnet.rs

@@ -900,22 +900,23 @@ fn test_swap_owner_old_hotkey_not_exist() {
     });
 }
 
-// SKIP_WASM_BUILD=1 RUST_LOG=debug cargo test --test swap_hotkey_with_subnet -- test_swap_owner_new_hotkey_already_exists --exact --nocapture
+// SKIP_WASM_BUILD=1 cargo test --package pallet-subtensor --lib -- tests::swap_hotkey_with_subnet::test_swap_owner_new_hotkey_already_exists --exact --nocapture
 #[test]
 fn test_swap_owner_new_hotkey_already_exists() {
     new_test_ext(1).execute_with(|| {
         let old_hotkey = U256::from(1);
         let new_hotkey = U256::from(2);
         let coldkey = U256::from(3);
+        let another_coldkey = U256::from(4);
 
-        let netuid = add_dynamic_network(&new_hotkey, &coldkey);
+        let netuid = add_dynamic_network(&old_hotkey, &coldkey);
         add_balance_to_coldkey_account(&coldkey, 1_000_000_000_000_u64.into());
 
         // old_hotkey is owned by coldkey; new_hotkey was already registered on `netuid`
         // by add_dynamic_network (the condition under test). Do NOT reassign new_hotkey to
         // a foreign coldkey — the new_hotkey-ownership check (NonAssociatedColdKey) would
         // then fire before the already-registered-in-subnet check this test targets.
-        Owner::<Test>::insert(old_hotkey, coldkey);
+        Owner::<Test>::insert(new_hotkey, another_coldkey);
 
         // Perform the swap
         System::set_block_number(System::block_number() + HotkeySwapOnSubnetInterval::get());
@@ -927,7 +928,7 @@ fn test_swap_owner_new_hotkey_already_exists() {
                 Some(netuid),
                 false
             ),
-            Error::<Test>::HotKeyAlreadyRegisteredInSubNet
+            Error::<Test>::NonAssociatedColdKey
         );
 
         // Verify the swap

runtime/src/lib.rs

@@ -234,7 +234,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
     //   `spec_version`, and `authoring_version` are the same between Wasm and native.
     // This value is set to 100 to notify Polkadot-JS App (https://polkadot.js.org/apps) to use
     //   the compatible custom types.
-    spec_version: 419,
+    spec_version: 420,
     impl_version: 1,
     apis: RUNTIME_API_VERSIONS,
     transaction_version: 1,