Add check for missing signature with fee'ed transaction

And update fetch-perf-libs version

fetch-perf-libs.sh

@@ -16,7 +16,7 @@ mkdir -p target/perf-libs
   cd target/perf-libs
   (
     set -x
-    curl https://solana-perf.s3.amazonaws.com/v0.11.0/x86_64-unknown-linux-gnu/solana-perf.tgz | tar zxvf -
+    curl https://solana-perf.s3.amazonaws.com/v0.11.1/x86_64-unknown-linux-gnu/solana-perf.tgz | tar zxvf -
   )
 
   if [[ -r solana-perf-CUDA_HOME.txt ]]; then

src/bank.rs

@@ -104,6 +104,9 @@ pub enum BankError {
 
     /// Loader call chain too deep
     CallChainTooDeep,
+
+    /// Transaction has a fee but has no signature present
+    MissingSignatureForFee,
 }
 
 pub type Result<T> = result::Result<T, BankError>;
@@ -637,7 +640,9 @@ impl Bank {
         error_counters: &mut ErrorCounters,
     ) -> Result<Vec<Account>> {
         // Copy all the accounts
-        if accounts.load(&tx.account_keys[0]).is_none() {
+        if tx.signatures.is_empty() && tx.fee != 0 {
+            Err(BankError::MissingSignatureForFee)
+        } else if accounts.load(&tx.account_keys[0]).is_none() {
             error_counters.account_not_found += 1;
             Err(BankError::AccountNotFound)
         } else if accounts.load(&tx.account_keys[0]).unwrap().tokens < tx.fee {