Removed check for double negative sign in custom format. Replaced by … (#2270)

* Removed check for double negative sign in custom format. Replaced by Math.Abs when formatting the string.

* Added more tests

* added comment

* Reverted to using regexp

* Added some additional checks for custom format.

Author: AdrianEPPlus

src/EPPlus/Utils/String/ValueToTextHandler.cs

@@ -76,7 +76,7 @@ internal static string FormatValue(object v, bool forWidthCalc, ExcelFormatTrans
             if (v == null) v = 0;
             var f = nf.GetFormatPart(v);
             isValidFormat = f.IsValid;
-            if(isValidFormat == false)
+            if (isValidFormat == false)
             {
                 return null;
             }
@@ -117,7 +117,7 @@ internal static string FormatValue(object v, bool forWidthCalc, ExcelFormatTrans
                         }
                         else
                         {
-                            return FormatNumber(d, format, overrideCultureInfo ?? nf.Culture);
+                            return FormatNumber(d, format, overrideCultureInfo ?? nf.Culture, nf.Formats.Count > 1);
                         }
                     }
                     else
@@ -215,22 +215,23 @@ internal static string FormatValue(object v, bool forWidthCalc, ExcelFormatTrans
             return v.ToString();
         }
 
-        private static string FormatNumber(double d, string format, CultureInfo cultureInfo)
+        private static string FormatNumber(double d, string format, CultureInfo cultureInfo, bool isNegativeFormat)
         {
             var s = FormatNumberExcel(d, format, cultureInfo);
             var ns = cultureInfo?.NumberFormat?.NegativeSign ?? "-";
             if (string.IsNullOrEmpty(s) == false && d < 0)
             {
-                return CheckAndRemoveNegativeSign(format, s, ns);
+                return CheckAndRemoveNegativeSign(format, s, ns, isNegativeFormat);
             }
             else
             {
                 return s;
             }
         }
 
-        private static string CheckAndRemoveNegativeSign(string format, string s, string ns)
+        private static string CheckAndRemoveNegativeSign(string format, string s, string ns, bool isNegativeFormat)
         {
+            //We should not use regexp, but it will do for now.
             //This regex pattern ^(\[[^\]]+\]|[\\'\""\*_])* removes:
             //                     \[[^\]]+\] : This part removes Anything inside square brackets
             //                                [\\'\""\*_] : This part removes Backslashes, quotes, asterisks and underlines
@@ -244,6 +245,10 @@ private static string CheckAndRemoveNegativeSign(string format, string s, string
             {
                 return s.Substring(1);
             }
+            else if ((s.StartsWith($"{ns}") || s.StartsWith($"-")) && !formatStartsWithNegative && isNegativeFormat)
+            {
+                return s.Remove(0, 1);
+            }
             else
             {
                 return s;

src/EPPlusTest/Issues/WorksheetIssues.cs

@@ -6,6 +6,7 @@
 using OfficeOpenXml.FormulaParsing;
 using OfficeOpenXml.FormulaParsing.Excel.Functions.Logical;
 using OfficeOpenXml.FormulaParsing.Excel.Functions.MathFunctions;
+using OfficeOpenXml.RichData;
 using OfficeOpenXml.SystemDrawing.Image;
 using OfficeOpenXml.SystemDrawing.Text;
 using System;
@@ -1085,10 +1086,30 @@ public void i2258()
         {
             var p = OpenTemplatePackage("repro2.xlsx");
             var ws = p.Workbook.Worksheets.First();
+
             var a1 = ws.Cells["A1"].Text;
-            var b1 = ws.Cells["B1"].Text;
             Assert.AreEqual("-/- 1 000", a1);
+
+            var b1 = ws.Cells["B1"].Text;
             Assert.AreEqual("-/- 2 000", b1);
+
+            var c1 = ws.Cells["C1"].Text;
+            Assert.AreEqual("3 000,00", c1);
+
+            var d1 = ws.Cells["D1"].Text;
+            Assert.AreEqual("(4000,000)", d1);
+
+            var a3 = ws.Cells["A3"].Text;
+            Assert.AreEqual("1000,000", a3);
+
+            var b3 = ws.Cells["B3"].Text;
+            Assert.AreEqual("(2000,000)", b3);
+            
+            var c3 = ws.Cells["C3"].Text;
+            Assert.AreEqual("-3000,000", c3);
+            
+            var d3 = ws.Cells["D3"].Text;
+            Assert.AreEqual("Negative 4000,000", d3);
         }
 
     }