Fix cyclic references handling in struct tree parent

DEVSIX-8616 Autoported commit. Original commit hash: [a0fc8b8fe]
aleks-ivanov · Oct 6, 2024 · 74fd7e5 · 74fd7e5
1 parent 0f8556a
commit 74fd7e5
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Showing 5 changed files with 21 additions and 4 deletions.
diff --git a/itext.tests/itext.kernel.tests/itext/kernel/utils/PdfMergerTest.cs b/itext.tests/itext.kernel.tests/itext/kernel/utils/PdfMergerTest.cs
@@ -134,6 +134,22 @@ public virtual void MergeDocumentTest02() {
                 , destinationFolder, "diff_"));
         }
 
+        [NUnit.Framework.Test]
+        public virtual void MergeDocumentWithCycleTagReferenceTest() {
+            String filename1 = sourceFolder + "doc1.pdf";
+            String filename2 = sourceFolder + "pdfWithCycleRefInParentTag.pdf";
+            String resultFile = destinationFolder + "pdfWithCycleRefInParentTag.pdf";
+            using (PdfDocument pdfDocument1 = new PdfDocument(new PdfReader(filename2))) {
+                using (PdfDocument pdfDocument2 = new PdfDocument(new PdfReader(filename1), CompareTool.CreateTestPdfWriter
+                    (resultFile).SetSmartMode(true))) {
+                    PdfMerger merger = new PdfMerger(pdfDocument2);
+                    merger.Merge(pdfDocument1, 1, pdfDocument1.GetNumberOfPages());
+                }
+            }
+            NUnit.Framework.Assert.IsNull(new CompareTool().CompareByContent(resultFile, sourceFolder + "cmp_pdfWithCycleRefInParentTag.pdf"
+                , destinationFolder, "diff_"));
+        }
+
         [NUnit.Framework.Test]
         [LogMessage(iText.IO.Logs.IoLogMessageConstant.SOURCE_DOCUMENT_HAS_ACROFORM_DICTIONARY)]
         public virtual void MergeDocumentTest03() {

diff --git a/...ernel.tests/resources/itext/kernel/utils/PdfMergerTest/cmp_pdfWithCycleRefInParentTag.pdf b/...ernel.tests/resources/itext/kernel/utils/PdfMergerTest/cmp_pdfWithCycleRefInParentTag.pdf
diff --git a/...xt.kernel.tests/resources/itext/kernel/utils/PdfMergerTest/pdfWithCycleRefInParentTag.pdf b/...xt.kernel.tests/resources/itext/kernel/utils/PdfMergerTest/pdfWithCycleRefInParentTag.pdf
diff --git a/itext/itext.kernel/itext/kernel/pdf/tagging/StructureTreeCopier.cs b/itext/itext.kernel/itext/kernel/pdf/tagging/StructureTreeCopier.cs
@@ -634,11 +634,12 @@ private static PdfDictionary GetTopmostParent(PdfMcr mcr) {
         }
 
         private static IList<PdfDictionary> RetrieveParents(PdfMcr mcr, bool all) {
-            IList<PdfDictionary> parents = new List<PdfDictionary>();
+            ICollection<PdfDictionary> parents = new LinkedHashSet<PdfDictionary>();
             IStructureNode firstParent = mcr.GetParent();
             PdfDictionary previous = null;
             PdfDictionary current = firstParent is PdfStructElem ? ((PdfStructElem)firstParent).GetPdfObject() : null;
-            while (current != null && !PdfName.StructTreeRoot.Equals(current.GetAsName(PdfName.Type))) {
+            while (current != null && !PdfName.StructTreeRoot.Equals(current.GetAsName(PdfName.Type)) && !parents.Contains
+                (current)) {
                 if (all) {
                     parents.Add(current);
                 }
@@ -648,7 +649,7 @@ private static IList<PdfDictionary> RetrieveParents(PdfMcr mcr, bool all) {
             if (!all) {
                 parents.Add(previous);
             }
-            return parents;
+            return new List<PdfDictionary>(parents);
         }
 
 //\cond DO_NOT_DOCUMENT

diff --git a/port-hash b/port-hash
@@ -1 +1 @@
-a6e77ae175f64fa2b5f619945eab96b1d23c371d
+a0fc8b8fe2956f080130695f69f406bc43a9f980
Original file line number	Diff line number	Diff line change
		@@ -1 +1 @@
		a6e77ae175f64fa2b5f619945eab96b1d23c371d
		a0fc8b8fe2956f080130695f69f406bc43a9f980