Permit paying oneself (#10337)

* Allow paying to oneself

* cargo fmt

* Permit pay-to-self in CLI

No test here because we're just removing an [untested] special case.

Fixes #10339

(cherry picked from commit 5d248fe)

# Conflicts:
#	runtime/src/system_instruction_processor.rs

cli/src/cli.rs

@@ -1584,11 +1584,6 @@ fn process_transfer(
 ) -> ProcessResult {
     let from = config.signers[from];
 
-    check_unique_pubkeys(
-        (&from.pubkey(), "cli keypair".to_string()),
-        (to, "to".to_string()),
-    )?;
-
     let (recent_blockhash, fee_calculator) =
         blockhash_query.get_blockhash_and_fee_calculator(rpc_client)?;
     let ixs = vec![system_instruction::transfer(&from.pubkey(), to, lamports)];

runtime/src/accounts.rs

@@ -1393,38 +1393,6 @@ mod tests {
         }
     }
 
-    #[test]
-    fn test_load_account_pay_to_self() {
-        let mut accounts: Vec<(Pubkey, Account)> = Vec::new();
-        let mut error_counters = ErrorCounters::default();
-
-        let keypair = Keypair::new();
-        let pubkey = keypair.pubkey();
-
-        let account = Account::new(10, 1, &Pubkey::default());
-        accounts.push((pubkey, account));
-
-        let instructions = vec![CompiledInstruction::new(0, &(), vec![0, 1])];
-        // Simulate pay-to-self transaction, which loads the same account twice
-        let tx = Transaction::new_with_compiled_instructions(
-            &[&keypair],
-            &[pubkey],
-            Hash::default(),
-            vec![native_loader::id()],
-            instructions,
-        );
-        let loaded_accounts = load_accounts(tx, &accounts, &mut error_counters);
-
-        assert_eq!(loaded_accounts.len(), 1);
-        assert_eq!(
-            loaded_accounts[0],
-            (
-                Err(TransactionError::InvalidAccountForFee),
-                Some(HashAgeKind::Extant)
-            )
-        );
-    }
-
     #[test]
     fn test_load_by_program_slot() {
         let accounts = Accounts::new(Vec::new());

runtime/src/bank.rs

@@ -4973,13 +4973,9 @@ mod tests {
         let _res = bank.process_transaction(&tx);
 
         assert_eq!(bank.get_balance(&key1.pubkey()), 1);
-
-        // TODO: Why do we convert errors to Oks?
-        //res[0].clone().unwrap_err();
-
         bank.get_signature_status(&tx.signatures[0])
             .unwrap()
-            .unwrap_err();
+            .unwrap();
     }
 
     fn new_from_parent(parent: &Arc<Bank>) -> Bank {