From 0b14384ab326552300e0349b9f66e11eb98ea9f4 Mon Sep 17 00:00:00 2001
From: JanKallman <jan.kallman@epplussoftware.com>
Date: Wed, 14 Jun 2023 08:49:50 +0200
Subject: [PATCH] Fixes incorrect circular reference exception - #905

---
 .../DependencyChain/DependenyChainFactory.cs   |  3 ++-
 .../FormulaParsing/CircularReferenceTests.cs   | 18 ++++++++++++++++++
 src/EPPlusTest/Issues.cs                       | 10 ++++++++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/EPPlus/FormulaParsing/DependencyChain/DependenyChainFactory.cs b/src/EPPlus/FormulaParsing/DependencyChain/DependenyChainFactory.cs
index f037f99ee..51d0d91b0 100644
--- a/src/EPPlus/FormulaParsing/DependencyChain/DependenyChainFactory.cs
+++ b/src/EPPlus/FormulaParsing/DependencyChain/DependenyChainFactory.cs
@@ -173,7 +173,8 @@ private static void FollowChain(DependencyChain depChain, ILexer lexer, ExcelWor
                         adr.SetRCFromTable(ws._package, new ExcelAddressBase(f.Row, f.Column, f.Row, f.Column));
                     }
 
-                    if (ws!=null && adr.WorkSheetName.Equals(ws.Name, StringComparison.OrdinalIgnoreCase) && string.IsNullOrEmpty(adr._wb) && adr.Collide(new ExcelAddressBase(f.Row, f.Column, f.Row, f.Column))!=ExcelAddressBase.eAddressCollition.No)
+                    if (adr.WorkSheetName.Equals((f.ws ?? ws)?.Name,
+                        StringComparison.OrdinalIgnoreCase) && string.IsNullOrEmpty(adr._wb) && adr.Collide(new ExcelAddressBase(f.Row, f.Column, f.Row, f.Column))!=ExcelAddressBase.eAddressCollition.No)
                     {
                         var tt = t.GetTokenTypeFlags() | TokenType.CircularReference;
                         f.Tokens[f.tokenIx] = t.CloneWithNewTokenType(tt);
diff --git a/src/EPPlusTest/FormulaParsing/CircularReferenceTests.cs b/src/EPPlusTest/FormulaParsing/CircularReferenceTests.cs
index d273c299f..25eed8392 100644
--- a/src/EPPlusTest/FormulaParsing/CircularReferenceTests.cs
+++ b/src/EPPlusTest/FormulaParsing/CircularReferenceTests.cs
@@ -164,5 +164,23 @@ public void IfShouldIgnoreCircularRefWhenIgnoredArg()
                 Assert.AreEqual(6, sheet.Cells["B4"].Value);
             }
         }
+        [TestMethod]
+        public void ReferenceToOtherSheetShouldNotGenerateACircularReference()
+        {
+            using (var package = new ExcelPackage())
+            {
+                var sheet1 = package.Workbook.Worksheets.Add("Sheet1");
+                var sheet2 = package.Workbook.Worksheets.Add("Sheet2");
+
+                sheet1.Cells["A1"].Value = 1d;
+                sheet1.Cells["A2"].Value = 3d;
+                sheet1.Cells["A3"].Formula = "=Sheet2!A1";
+
+                sheet2.Cells["A1"].Formula = "=Sheet1!A1";
+
+                package.Workbook.Calculate();
+            }
+        }
+
     }
 }
diff --git a/src/EPPlusTest/Issues.cs b/src/EPPlusTest/Issues.cs
index 78f300302..0fa8e40d9 100644
--- a/src/EPPlusTest/Issues.cs
+++ b/src/EPPlusTest/Issues.cs
@@ -5003,6 +5003,16 @@ public void s474()
                 OfficeOpenXml.DataValidation.Contracts.IExcelDataValidationList validationList = 
                     sheet.DataValidations.AddListValidation(sheet.Cells[startRow, columnCount, sheetRows - 1, columnCount].Address);
 
+                SaveAndCleanup(p);
+            }
+        }
+        [TestMethod]
+        public void I892()
+        {
+            using (var p = OpenTemplatePackage("TEST_20230607.xlsx"))
+            {
+                p.Encryption.Password = "P@ssw0rd";
+
                 SaveAndCleanup(p);
             }
         }