From f9a74b51ef2e52f738c097032e4d0f460c1b656a Mon Sep 17 00:00:00 2001
From: Michael Vines <mvines@gmail.com>
Date: Thu, 24 Sep 2020 10:10:27 -0700
Subject: [PATCH] Add feature to resolve spl-token v2 multisig bug

---
 runtime/src/bank.rs        | 36 ++++++++++++++++++++++++++++++++++++
 runtime/src/feature_set.rs |  5 +++++
 2 files changed, 41 insertions(+)

diff --git a/runtime/src/bank.rs b/runtime/src/bank.rs
index 41d9cc6088..c237ce723e 100644
--- a/runtime/src/bank.rs
+++ b/runtime/src/bank.rs
@@ -3567,6 +3567,10 @@ impl Bank {
             self.rent_collector.rent.burn_percent = 50; // 50% rent burn
         }
 
+        if new_feature_activations.contains(&feature_set::spl_token_v2_multisig_fix::id()) {
+            self.apply_spl_token_v2_multisig_fix();
+        }
+
         self.ensure_builtins(init_finish_or_warp, &new_feature_activations);
         self.reinvoke_entered_epoch_callback(initiate_callback);
         self.recheck_cross_program_support();
@@ -3674,6 +3678,15 @@ impl Bank {
         self.set_compute_budget(compute_budget);
     }
 
+    fn apply_spl_token_v2_multisig_fix(&mut self) {
+        if let Some(mut account) = self.get_account(&inline_spl_token_v2_0::id()) {
+            self.capitalization.fetch_sub(account.lamports, Relaxed);
+            account.lamports = 0;
+            self.store_account(&inline_spl_token_v2_0::id(), &account);
+            self.remove_executor(&inline_spl_token_v2_0::id());
+        }
+    }
+
     fn reconfigure_token2_native_mint(&mut self) {
         let reconfigure_token2_native_mint = match self.cluster_type() {
             ClusterType::Development => true,
@@ -9202,4 +9215,27 @@ mod tests {
         assert!(new_activations.is_empty());
         assert!(bank.feature_set.is_active(&test_feature));
     }
+
+    #[test]
+    fn test_spl_token_v2_multisig_fix() {
+        let (genesis_config, _mint_keypair) = create_genesis_config(0);
+        let mut bank = Bank::new(&genesis_config);
+
+        // Setup a simulated account
+        bank.add_account_and_update_capitalization(
+            &inline_spl_token_v2_0::id(),
+            &Account {
+                lamports: 100,
+                ..Account::default()
+            },
+        );
+        assert_eq!(bank.get_balance(&inline_spl_token_v2_0::id()), 100);
+        let original_capitalization = bank.capitalization();
+
+        bank.apply_spl_token_v2_multisig_fix();
+
+        // Account is now empty, and the account lamports were burnt
+        assert_eq!(bank.get_balance(&inline_spl_token_v2_0::id()), 0);
+        assert_eq!(bank.capitalization(), original_capitalization - 100);
+    }
 }
diff --git a/runtime/src/feature_set.rs b/runtime/src/feature_set.rs
index 618cb98878..c7e7d9be8e 100644
--- a/runtime/src/feature_set.rs
+++ b/runtime/src/feature_set.rs
@@ -21,6 +21,10 @@ pub mod pico_inflation {
     solana_sdk::declare_id!("GaBtBJvmS4Arjj5W1NmFcyvPjsHN38UGYDq2MDwbs9Qu");
 }
 
+pub mod spl_token_v2_multisig_fix {
+    solana_sdk::declare_id!("E5JiFDQCwyC6QfT9REFyMpfK2mHcmv1GUDySU1Ue7TYv");
+}
+
 lazy_static! {
     /// Map of feature identifiers to user-visible description
     pub static ref FEATURE_NAMES: HashMap<Pubkey, &'static str> = [
@@ -28,6 +32,7 @@ lazy_static! {
         (secp256k1_program_enabled::id(), "secp256k1 program"),
         (consistent_recent_blockhashes_sysvar::id(), "consistent recentblockhashes sysvar"),
         (pico_inflation::id(), "pico-inflation"),
+        (spl_token_v2_multisig_fix::id(), "spl-token multisig fix"),
         /*************** ADD NEW FEATURES HERE ***************/
     ]
     .iter()