Fixed duplicate events from triggering (#404).

_version.d.ts

@@ -1 +1 @@
-export declare const version = "4.0.22";
+export declare const version = "4.0.23";

_version.js

@@ -1,3 +1,3 @@
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-exports.version = "4.0.22";
+exports.version = "4.0.23";

dist/ethers.js

@@ -1,7 +1,7 @@
 (function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.ethers = f()}})(function(){var define,module,exports;return (function(){function r(e,n,t){function o(i,f){if(!n[i]){if(!e[i]){var c="function"==typeof require&&require;if(!f&&c)return c(i,!0);if(u)return u(i,!0);var a=new Error("Cannot find module '"+i+"'");throw a.code="MODULE_NOT_FOUND",a}var p=n[i]={exports:{}};e[i][0].call(p.exports,function(r){var n=e[i][1][r];return o(n||r)},p,p.exports,r,e,n,t)}return n[i].exports}for(var u="function"==typeof require&&require,i=0;i<t.length;i++)o(t[i]);return o}return r})()({1:[function(require,module,exports){
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-exports.version = "4.0.22";
+exports.version = "4.0.23";
 
 },{}],2:[function(require,module,exports){
 "use strict";
@@ -10189,7 +10189,7 @@ function checkTransactionReceiptLog(log) {
 }
 var formatTransactionReceipt = {
     to: allowNull(address_1.getAddress, null),
-    from: address_1.getAddress,
+    from: allowNull(address_1.getAddress, null),
     contractAddress: allowNull(address_1.getAddress, null),
     transactionIndex: checkNumber,
     root: allowNull(checkHash),

dist/ethers.types.txt

@@ -265,7 +265,7 @@ declare module 'ethers/utils/shims' {
 }
 
 declare module 'ethers/_version' {
-    export const version = "4.0.22";
+    export const version = "4.0.23";
 }
 
 declare module 'ethers/utils/bignumber' {

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "ethers",
-  "version": "4.0.22",
+  "version": "4.0.23",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ethers",
-  "version": "4.0.22",
+  "version": "4.0.23",
   "description": "Ethereum wallet library.",
   "main": "./index.js",
   "types": "./index.d.ts",

providers/base-provider.js

@@ -281,7 +281,7 @@ function checkTransactionReceiptLog(log) {
 }
 var formatTransactionReceipt = {
     to: allowNull(address_1.getAddress, null),
-    from: address_1.getAddress,
+    from: allowNull(address_1.getAddress, null),
     contractAddress: allowNull(address_1.getAddress, null),
     transactionIndex: checkNumber,
     root: allowNull(checkHash),

src.ts/_version.ts

@@ -1 +1 @@
-export const version = "4.0.22";
+export const version = "4.0.23";

src.ts/providers/base-provider.ts

@@ -611,8 +611,13 @@ export class BaseProvider extends Provider {
             let newBalances: any = {};
 
             // Find all transaction hashes we are waiting on
+            let uniqueEventTags: { [ tag: string ]: boolean } = { };
             this._events.forEach((event) => {
-                let comps = event.tag.split(':');
+                uniqueEventTags[event.tag] = true;
+            });
+
+            Object.keys(uniqueEventTags).forEach((tag) => {
+                let comps = tag.split(':');
                 switch (comps[0]) {
                     case 'tx': {
                         let hash = comps[1];