_checkErrorArg return null or error

cell/model/FormulaObjects/mathematicFunctions.js

@@ -638,7 +638,7 @@
 		argClone[2] = argClone[2] ? argClone[2].tocNumber() : new cNumber(0);
 
 		var argError;
-		if(false !== (argError = this._checkErrorArg(argClone))){
+		if (argError = this._checkErrorArg(argClone)) {
 			return this.value = argError;
 		}
 
@@ -801,7 +801,7 @@
 		argClone[2] = argClone[2] ? argClone[2].tocNumber() : new cNumber(0);
 
 		var argError;
-		if(false !== (argError = this._checkErrorArg(argClone))){
+		if (argError = this._checkErrorArg(argClone)) {
 			return this.value = argError;
 		}
 
@@ -856,7 +856,7 @@
 		argClone[1] = argClone[1] ? argClone[1].tocNumber() : new cNumber(1);
 
 		var argError;
-		if(false !== (argError = this._checkErrorArg(argClone))){
+		if (argError = this._checkErrorArg(argClone)) {
 			return this.value = argError;
 		}
 
@@ -995,7 +995,7 @@
 		argClone[1] = argClone[1].tocNumber();
 
 		var argError;
-		if(false !== (argError = this._checkErrorArg(argClone))){
+		if (argError = this._checkErrorArg(argClone)) {
 			return this.value = argError;
 		}
 
@@ -1360,7 +1360,7 @@
 		argClone[1] = argClone[1].tocNumber();
 
 		var argError;
-		if(false !== (argError = this._checkErrorArg(argClone))){
+		if (argError = this._checkErrorArg(argClone)) {
 			return this.value = argError;
 		}
 
@@ -1833,7 +1833,7 @@
 		argClone[1] = argClone[1] ? argClone[1].tocNumber() : new cNumber(1);
 
 		var argError;
-		if(false !== (argError = this._checkErrorArg(argClone))){
+		if (argError = this._checkErrorArg(argClone)) {
 			return this.value = argError;
 		}
 
@@ -1885,7 +1885,7 @@
 		argClone[2] = argClone[2] ? argClone[2].tocNumber() : new cNumber(0);
 
 		var argError;
-		if(false !== (argError = this._checkErrorArg(argClone))){
+		if (argError = this._checkErrorArg(argClone)) {
 			return this.value = argError;
 		}
 
@@ -2088,7 +2088,7 @@
 		argClone[1] = argClone[1] ? argClone[1].tocNumber() : new cNumber(1);
 
 		var argError;
-		if(false !== (argError = this._checkErrorArg(argClone))){
+		if (argError = this._checkErrorArg(argClone)) {
 			return this.value = argError;
 		}
 

cell/model/FormulaObjects/parserFormula.js

@@ -2415,15 +2415,12 @@ parserHelp.setDigitSeparator(AscCommon.g_oDefaultCultureInfo.NumberDecimalSepara
 		return arg;
 	};
 	cBaseFunction.prototype._checkErrorArg = function (argArray) {
-		var res = false;
-		for(var i = 0; i < argArray.length; i++)
-		{
-			if(argArray[i] instanceof cError)
-			{
+		for (var i = 0; i < argArray.length; i++) {
+			if (cElementType.error === argArray[i].type) {
 				return argArray[i];
 			}
 		}
-		return res;
+		return null;
 	};
 
 	/** @constructor */