don't dissolve root

Author: JohnReedV

pallets/subtensor/src/coinbase/root.rs

@@ -367,7 +367,7 @@ impl<T: Config> Pallet<T> {
     pub fn do_dissolve_network(netuid: NetUid) -> dispatch::DispatchResult {
         // 1. --- The network exists?
         ensure!(
-            Self::if_subnet_exist(netuid),
+            Self::if_subnet_exist(netuid) && netuid != NetUid::ROOT,
             Error::<T>::SubNetworkDoesNotExist
         );
 
@@ -418,7 +418,7 @@ impl<T: Config> Pallet<T> {
         for (uid_i, weights_i) in <Weights<T> as frame_support::storage::IterableStorageDoubleMap<
             NetUid,
             u16,
-            sp_std::vec::Vec<(u16, u16)>,
+            Vec<(u16, u16)>,
         >>::iter_prefix(NetUid::ROOT)
         {
             let mut modified_weights = weights_i.clone();

pallets/subtensor/src/tests/networks.rs

@@ -1114,7 +1114,7 @@ fn prune_selection_complex_state_exhaustive() {
         // Remove n5; now n6 (price=0) should be selected.
         // This validates robustness to holes / non-contiguous netuids.
         // ---------------------------------------------------------------------
-        SubtensorModule::remove_network(n5);
+        SubtensorModule::do_dissolve_network(n5).expect("Expected not to panic");
         assert_eq!(
             SubtensorModule::get_network_to_prune(),
             Some(n6),