Track IndirectReference instead of only ObjectNumber when checking for cycles during indirect reference resolutionv and add test

src/UglyToad.PdfPig.Tests/Integration/GithubIssuesTests.cs

@@ -7,6 +7,27 @@
 
     public class GithubIssuesTests
     {
+        [Fact]
+        public void Issue1096()
+        {
+            // Ensure no StackOverflowException
+            // (already fixed by https://github.com/UglyToad/PdfPig/pull/1097)
+            
+            var path = IntegrationHelpers.GetSpecificTestDocumentPath("issue_1096.pdf");
+
+            using (var document = PdfDocument.Open(path, new ParsingOptions() { UseLenientParsing = true }))
+            {
+                for (int p = 1; p <= document.NumberOfPages; p++)
+                {
+                    var page = document.GetPage(p);
+                    foreach (var image in page.GetImages())
+                    {
+                        Assert.NotNull(image);
+                    }
+                }
+            }
+        }
+
         [Fact]
         public void Issue1067()
         {

src/UglyToad.PdfPig/PdfExtensions.cs

@@ -122,12 +122,12 @@
         /// Returns an equivalent token where any indirect references of child objects are
         /// recursively traversed and resolved.
         /// </summary>
-        internal static T? Resolve<T>(this T? token, IPdfTokenScanner scanner, List<long>? visited = null) where T : IToken
+        internal static T? Resolve<T>(this T? token, IPdfTokenScanner scanner, List<IndirectReference>? visited = null) where T : IToken
         {
             return (T?)ResolveInternal(token, scanner, visited ?? []);
         }
 
-        private static IToken? ResolveInternal(this IToken? token, IPdfTokenScanner scanner, List<long> visited)
+        private static IToken? ResolveInternal(this IToken? token, IPdfTokenScanner scanner, List<IndirectReference> visited)
         {
             if (token is StreamToken stream)
             {
@@ -142,12 +142,12 @@
                     var value = kvp.Value;
                     if (kvp.Value is IndirectReferenceToken reference)
                     {
-                        if (visited.Contains(reference.Data.ObjectNumber))
+                        if (visited.Contains(reference.Data))
                         {
                             continue;
                         }
                         value = scanner.Get(reference.Data)?.Data;
-                        visited.Add(reference.Data.ObjectNumber);
+                        visited.Add(reference.Data);
                     }
                     resolvedItems[NameToken.Create(kvp.Key)] = ResolveInternal(value, scanner, visited);
                 }