Estimate_gas return issues (polkadot-evm#363)

* Return error when OutOfFund

* Fix estimate_gas early return

* Update comments

* Update changelog

* Update message info

client/rpc/CHANGELOG.md

@@ -2,4 +2,5 @@
 
 ## Unreleased
 
-* `EthPubSubApi::new` takes an additional `overrides` parameter.
+* `EthPubSubApi::new` takes an additional `overrides` parameter.
+* Fix `estimate_gas` inaccurate issue.

client/rpc/src/eth.rs

@@ -891,17 +891,17 @@ impl<B, C, P, CT, BE, H: ExHashT> EthApiT for EthApi<B, C, P, CT, BE, H> where
 					}
 
 					Err(err) => {
-						// if Err == OutofGas or OutofFund, we need more gas
+						// if Err == OutofGas, we need more gas
 						if err.code == ErrorCode::ServerError(0) {
 							lower = mid;
 							mid = (lower + upper + 1) / 2;
 							if mid == lower {
 								break;
 							}
+						} else {
+							// Other errors, return directly
+							return Err(err);
 						}
-
-						// Other errors, return directly
-						return Err(err);
 					}
 				}
 			}

client/rpc/src/lib.rs

@@ -168,11 +168,11 @@ pub fn error_on_execution_failure(reason: &ExitReason, data: &[u8]) -> Result<()
 	match reason {
 		ExitReason::Succeed(_) => Ok(()),
 		ExitReason::Error(e) => {
-			if *e == ExitError::OutOfGas || *e == ExitError::OutOfFund {
+			if *e == ExitError::OutOfGas {
 				// `ServerError(0)` will be useful in estimate gas
 				return Err(Error {
 					code: ErrorCode::ServerError(0),
-					message: format!("out of gas or fund"),
+					message: format!("out of gas"),
 					data: None,
 				});
 			}