From 224624cc7d0e5ce93d6797df20a0fb1289948b83 Mon Sep 17 00:00:00 2001
From: swmal <{ID}+username}@users.noreply.github.com>
Date: Mon, 27 Jul 2026 15:43:51 +0200
Subject: [PATCH] #2441 - Added DisableImageFunctionDownloads property to
 ExcelCalculationOption

---
 .../RpnOptimizedDependencyChain.cs                |  1 +
 .../FormulaParsing/ExcelCalculationOption.cs      |  7 +++++++
 .../Functions/RefAndLookup/ImageFunctionTests.cs  | 15 +++++++++++++++
 3 files changed, 23 insertions(+)

diff --git a/src/EPPlus/FormulaParsing/DependencyChain/RpnOptimizedDependencyChain.cs b/src/EPPlus/FormulaParsing/DependencyChain/RpnOptimizedDependencyChain.cs
index 72678303a5..34f64b6ab3 100644
--- a/src/EPPlus/FormulaParsing/DependencyChain/RpnOptimizedDependencyChain.cs
+++ b/src/EPPlus/FormulaParsing/DependencyChain/RpnOptimizedDependencyChain.cs
@@ -44,6 +44,7 @@ public RpnOptimizedDependencyChain(ExcelWorkbook wb, ExcelCalculationOption opti
                 config.CacheExpressions = options.CacheExpressions;
                 config.PrecisionAndRoundingStrategy = options.PrecisionAndRoundingStrategy;
                 config.AlwaysRefreshImageFunction = options.AlwaysRefreshImageFunction;
+                config.DisableImageFunctionDownloads = options.DisableImageFunctionDownloads;
                 config.EnableUnicodeAwareStringOperations = options.EnableUnicodeAwareStringOperations;
             });
 
diff --git a/src/EPPlus/FormulaParsing/ExcelCalculationOption.cs b/src/EPPlus/FormulaParsing/ExcelCalculationOption.cs
index 3e61ec6539..809de23ab4 100644
--- a/src/EPPlus/FormulaParsing/ExcelCalculationOption.cs
+++ b/src/EPPlus/FormulaParsing/ExcelCalculationOption.cs
@@ -116,6 +116,13 @@ public bool AlwaysRefreshImageFunction
             set; 
         } = false;
 
+        /// <summary>
+        /// If true the IMAGE function will never download external content in formula calculation.
+        /// It will instead return the NAME error as if the function was not implemented.
+        /// NB! This property overrides the <see cref="AlwaysRefreshImageFunction"/> property if set to true.
+        /// </summary>
+        public bool DisableImageFunctionDownloads { get; set; } = false;
+
         /// <summary>
         /// Enables Unicode-aware string operations, ensuring correct handling of surrogate pairs for comparisons, substrings, and sorting within the library.
         /// </summary>
diff --git a/src/EPPlusTest/FormulaParsing/Excel/Functions/RefAndLookup/ImageFunctionTests.cs b/src/EPPlusTest/FormulaParsing/Excel/Functions/RefAndLookup/ImageFunctionTests.cs
index a4d6608a54..720f13623f 100644
--- a/src/EPPlusTest/FormulaParsing/Excel/Functions/RefAndLookup/ImageFunctionTests.cs
+++ b/src/EPPlusTest/FormulaParsing/Excel/Functions/RefAndLookup/ImageFunctionTests.cs
@@ -148,5 +148,20 @@ public void ImageTest_ShouldReturnNameErrorWhenServiceIsNull()
 
             Assert.AreEqual(ExcelErrorValue.Create(eErrorType.Name), sheet.Cells["A1"].Value);
         }
+
+        [TestMethod]
+        public void ImageTest_ShouldNotDownloadWhenDownloadsDisabled()
+        {
+            using var package = new ExcelPackage();
+            var httpsService = new TestHttpsService();
+            package.Settings.ImageFunctionService = httpsService;
+            var sheet = package.Workbook.Worksheets.Add("Sheet1");
+            sheet.Cells["A1"].Formula = "IMAGE(\"https://epplussoftware.com/img/EPPlus-logo-full.png\", \"Alt text\", 1)";
+
+            sheet.Calculate(opt => opt.DisableImageFunctionDownloads = true);
+
+            Assert.AreEqual(0, httpsService.NumberOfCalls, "the download service should not be called when downloads are disabled");
+            Assert.AreEqual(ExcelErrorValue.Create(eErrorType.Name), sheet.Cells["A1"].Value);
+        }
     }
 }