Optimization and increased security on token transfer operations

aave-core/sources/aave-pool/pool_token_logic.move

@@ -123,6 +123,7 @@ module aave_pool::pool_token_logic {
         amount: u256,
         a_token_address: address
     ) {
+        assert!(amount > 0, error_config::get_einvalid_amount());
         let sender_address = signer::address_of(sender);
         let underlying_asset =
             a_token_factory::get_underlying_asset_address(a_token_address);

aave-core/sources/aave-tokens/token_base.move

@@ -499,6 +499,9 @@ module aave_pool::token_base {
         index: u256,
         metadata_address: address
     ) acquires ManagedFungibleAsset, TokenBaseState {
+        if (amount == 0) {
+            return;
+        };
         // NOTE: in `ray_div`, while `amount` can be less precision than Ray
         //       precision, `index` must be expressed in Ray precision.
         let amount_scaled = wad_ray_math::ray_div(amount, index);