fix

Author: linzhijun

csharp/ToolGood.Algorithm/Internals/Functions/String/Function_REPLACE.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Text;
 using ToolGood.Algorithm.Enums;
@@ -26,6 +26,9 @@ public override Operand Evaluate(AlgorithmEngine engine, Func<AlgorithmEngine, s
 
 				var old = args22.TextValue;
 				var newstr = args32.TextValue;
+				if(old.Length == 0 || oldtext.IndexOf(old, StringComparison.Ordinal) < 0) {
+					return args1;
+				}
 				return Operand.Create(oldtext.Replace(old, newstr));
 			}
 

csharp/ToolGood.Algorithm/Internals/Functions/String/Function_REPT.cs

@@ -28,11 +28,17 @@ public override Operand Evaluate(AlgorithmEngine engine, Func<AlgorithmEngine, s
 			if (length == 0) {
 				return Operand.Create(string.Empty);
 			}
-			if (newtext.Length > 0 && length > 32767 / newtext.Length) {
+			if (newtext.Length == 0) {
+				return args1;
+			}
+			if (length > 32767 / newtext.Length) {
 				return ParameterError(2);
 			}
+			if (length == 1) {
+				return args1;
+			}
 			var sb = new StringBuilder(newtext.Length * length);
-			for (int i = 0; i < length; i++) {
+			for(int i = 0; i < length; i++) {
 				sb.Append(newtext);
 			}
 			return Operand.Create(sb.ToString());

csharp/ToolGood.Algorithm/Internals/Functions/String/Function_TRIM.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Text.RegularExpressions;
 using ToolGood.Algorithm.Enums;
@@ -21,6 +21,9 @@ public override Operand Evaluate(AlgorithmEngine engine, Func<AlgorithmEngine, s
 			if (args1.IsErrorOrNone) { return args1; }
 			var text = args1.TextValue.Trim();
 			text = s_multipleSpaces.Replace(text, " ");
+			if(text.Equals(args1.TextValue)) {
+				return args1;
+			}
 			return Operand.Create(text);
 		}
 		public override OperandType GetResultType()