Copy parent field if it is not present in the destination document

Previously we copied its children, but not the parent itself

DEVSIX-4902

Author: ars18wrw

forms/src/main/java/com/itextpdf/forms/PdfPageFormCopier.java

@@ -167,12 +167,14 @@ private void copyParentFormField(PdfPage toPage, Map<String, PdfFormField> field
                                      PdfAnnotation annot, PdfFormField parentField) {
         PdfString parentName = parentField.getFieldName();
         if (!fieldsTo.containsKey(parentName.toUnicodeString())) {
+            // no such field, hence we should simply add it
             PdfFormField field = createParentFieldCopy(annot.getPdfObject(), documentTo);
             PdfArray kids = field.getKids();
             field.getPdfObject().remove(PdfName.Kids);
             formTo.addField(field, toPage);
             field.getPdfObject().put(PdfName.Kids, kids);
         } else {
+            // it is either a field (field name will not be null) or a widget (field name is not null)
             PdfFormField field = makeFormField(annot.getPdfObject());
             if (field == null) {
                 return;
@@ -190,18 +192,36 @@ private void copyParentFormField(PdfPage toPage, Map<String, PdfFormField> field
                             fieldsTo);
                 }
             } else {
-                if (!parentField.getKids().contains(field.getPdfObject())) {
+                if (!parentField.getKids().contains(field.getPdfObject())
+                        && formTo.getFields().contains(parentField.getPdfObject())) {
+                    // its parent is already a field of the resultant document,
+                    // hence we only need to update its children
                     HashSet<String> existingFields = new HashSet<>();
                     getAllFieldNames(formTo.getFields(), existingFields);
                     addChildToExistingParent(annot.getPdfObject(), existingFields);
+                } else {
+                    // its parent is not a field of the resultant document, but the latter contains
+                    // a field of the same name, therefore we should merge them (note that merging in this context
+                    // differs from merging a widget and an annotation into a single entity)
+                    PdfFormField mergedField = mergeFieldsWithTheSameName(field);
+                    // we need to add the field not to its representation (#getFormFields()), but to
+                    // /Fields entry of the acro form
+                    formTo.addField(mergedField, toPage);
                 }
             }
         }
     }
 
     private PdfFormField mergeFieldsWithTheSameName(PdfFormField newField) {
-        String fullFieldName = newField.getFieldName().toUnicodeString();
         PdfString fieldName = newField.getPdfObject().getAsString(PdfName.T);
+        if (null == fieldName) {
+            fieldName = newField.getParent().getAsString(PdfName.T);
+        }
+
+        String fullFieldName = fieldName.toUnicodeString();
+        if (null != newField.getFieldName()) {
+            fullFieldName = newField.getFieldName().toUnicodeString();
+        }
 
         logger.warn(MessageFormatUtil.format(LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD, fullFieldName));
 

forms/src/test/java/com/itextpdf/forms/FormFieldFlatteningTest.java

@@ -254,7 +254,7 @@ private static void fillTextFieldsThenFlattenThenCompare(String testName) throws
     }
 
     @Test
-    @LogMessages(messages = {@LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD, count = 3)})
+    @LogMessages(messages = {@LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD, count = 5)})
     //Logging is expected since there are duplicate field names
     //isReadOnly should be true after DEVSIX-2156
     public void flattenReadOnly() throws IOException {

forms/src/test/java/com/itextpdf/forms/PdfFormCopyTest.java

@@ -53,6 +53,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.test.annotations.LogMessage;
 import com.itextpdf.test.annotations.LogMessages;
 import com.itextpdf.test.annotations.type.IntegrationTest;
+
 import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -73,7 +74,7 @@ public static void beforeClass() {
 
     @Test
     @LogMessages(messages = {
-            @LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD, count = 13)
+            @LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD, count = 32)
     })
     public void copyFieldsTest01() throws IOException, InterruptedException {
         String srcFilename1 = sourceFolder + "appearances1.pdf";
@@ -328,7 +329,7 @@ public void copyFieldsTest06() throws IOException, InterruptedException {
 
     @Test
     @LogMessages(messages = {
-            @LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD, count = 13)
+            @LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD, count = 32)
     })
     public void copyFieldsTest07() throws IOException, InterruptedException {
         String srcFilename = sourceFolder + "datasheet.pdf";
@@ -350,7 +351,7 @@ public void copyFieldsTest07() throws IOException, InterruptedException {
 
     @Test
     @LogMessages(messages = {
-            @LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD, count = 13)
+            @LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD, count = 32)
     })
     public void copyFieldsTest08() throws IOException, InterruptedException {
         String srcFilename1 = sourceFolder + "appearances1.pdf";
@@ -378,7 +379,7 @@ public void copyFieldsTest08() throws IOException, InterruptedException {
 
     @Test
     @LogMessages(messages = {
-            @LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD, count = 26)
+            @LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD, count = 64)
     })
     public void copyFieldsTest09() throws IOException, InterruptedException {
         String srcFilename = sourceFolder + "datasheet.pdf";
@@ -596,4 +597,103 @@ public void copyAndEditRadioButtons() throws IOException, InterruptedException {
 
         Assert.assertNull(new CompareTool().compareByContent(destFilename, cmpFileName, destinationFolder, "diff_"));
     }
+
+    @Test
+    @LogMessages(messages = {
+            @LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD)
+    })
+    public void mergeMergedFieldAndMergedFieldTest() throws IOException, InterruptedException {
+        String srcFileName1 = sourceFolder + "fieldMergedWithWidget.pdf";
+        String destFilename = destinationFolder + "mergeMergedFieldAndMergedFieldTest.pdf";
+        String cmpFileName = sourceFolder + "cmp_mergeMergedFieldAndMergedFieldTest.pdf";
+
+        try (
+                PdfWriter writer = new PdfWriter(destFilename);
+                PdfDocument resultPdfDocument = new PdfDocument(writer);
+                PdfReader reader1 = new PdfReader(srcFileName1);
+                PdfDocument sourceDoc1 = new PdfDocument(reader1);) {
+            PdfAcroForm.getAcroForm(resultPdfDocument, true);
+            PdfPageFormCopier formCopier = new PdfPageFormCopier();
+
+            sourceDoc1.copyPagesTo(1, sourceDoc1.getNumberOfPages(), resultPdfDocument, formCopier);
+            sourceDoc1.copyPagesTo(1, sourceDoc1.getNumberOfPages(), resultPdfDocument, formCopier);
+        }
+
+        Assert.assertNull(new CompareTool().compareByContent(destFilename, cmpFileName, destinationFolder, "diff_"));
+    }
+
+    @Test
+    @LogMessages(messages = {
+            @LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD, count = 2)
+    })
+    public void mergeMergedFieldAndTwoWidgetsTest() throws IOException, InterruptedException {
+        String srcFileName1 = sourceFolder + "fieldMergedWithWidget.pdf";
+        String srcFileName2 = sourceFolder + "fieldTwoWidgets.pdf";
+        String destFilename = destinationFolder + "mergeMergedFieldAndTwoWidgetsTest.pdf";
+        String cmpFileName = sourceFolder + "cmp_mergeMergedFieldAndTwoWidgetsTest.pdf";
+
+        try (
+                PdfWriter writer = new PdfWriter(destFilename);
+                PdfDocument resultPdfDocument = new PdfDocument(writer);
+                PdfReader reader1 = new PdfReader(srcFileName1);
+                PdfDocument sourceDoc1 = new PdfDocument(reader1);
+                PdfReader reader2 = new PdfReader(srcFileName2);
+                PdfDocument sourceDoc2 = new PdfDocument(reader2);) {
+            PdfAcroForm.getAcroForm(resultPdfDocument, true);
+            PdfPageFormCopier formCopier = new PdfPageFormCopier();
+
+            sourceDoc1.copyPagesTo(1, sourceDoc1.getNumberOfPages(), resultPdfDocument, formCopier);
+            sourceDoc2.copyPagesTo(1, sourceDoc2.getNumberOfPages(), resultPdfDocument, formCopier);
+        }
+
+        Assert.assertNull(new CompareTool().compareByContent(destFilename, cmpFileName, destinationFolder, "diff_"));
+    }
+
+    @Test
+    @LogMessages(messages = {
+            @LogMessage(messageTemplate = LogMessageConstant.DOCUMENT_ALREADY_HAS_FIELD)
+    })
+    public void mergeTwoWidgetsAndMergedFieldTest() throws IOException, InterruptedException {
+        String srcFileName1 = sourceFolder + "fieldMergedWithWidget.pdf";
+        String srcFileName2 = sourceFolder + "fieldTwoWidgets.pdf";
+        String destFilename = destinationFolder + "mergeTwoWidgetsAndMergedFieldTest.pdf";
+        String cmpFileName = sourceFolder + "cmp_mergeTwoWidgetsAndMergedFieldTest.pdf";
+
+        try (
+                PdfWriter writer = new PdfWriter(destFilename);
+                PdfDocument resultPdfDocument = new PdfDocument(writer);
+                PdfReader reader1 = new PdfReader(srcFileName1);
+                PdfDocument sourceDoc1 = new PdfDocument(reader1);
+                PdfReader reader2 = new PdfReader(srcFileName2);
+                PdfDocument sourceDoc2 = new PdfDocument(reader2);) {
+            PdfAcroForm.getAcroForm(resultPdfDocument, true);
+            PdfPageFormCopier formCopier = new PdfPageFormCopier();
+
+            sourceDoc2.copyPagesTo(1, sourceDoc2.getNumberOfPages(), resultPdfDocument, formCopier);
+            sourceDoc1.copyPagesTo(1, sourceDoc1.getNumberOfPages(), resultPdfDocument, formCopier);
+        }
+
+        Assert.assertNull(new CompareTool().compareByContent(destFilename, cmpFileName, destinationFolder, "diff_"));
+    }
+
+    @Test
+    public void mergeTwoWidgetsAndTwoWidgetsTest() throws IOException, InterruptedException {
+        String srcFileName2 = sourceFolder + "fieldTwoWidgets.pdf";
+        String destFilename = destinationFolder + "mergeTwoWidgetsAndTwoWidgetsTest.pdf";
+        String cmpFileName = sourceFolder + "cmp_mergeTwoWidgetsAndTwoWidgetsTest.pdf";
+
+        try (
+                PdfWriter writer = new PdfWriter(destFilename);
+                PdfDocument resultPdfDocument = new PdfDocument(writer);
+                PdfReader reader2 = new PdfReader(srcFileName2);
+                PdfDocument sourceDoc2 = new PdfDocument(reader2);) {
+            PdfAcroForm.getAcroForm(resultPdfDocument, true);
+            PdfPageFormCopier formCopier = new PdfPageFormCopier();
+
+            sourceDoc2.copyPagesTo(1, sourceDoc2.getNumberOfPages(), resultPdfDocument, formCopier);
+            sourceDoc2.copyPagesTo(1, sourceDoc2.getNumberOfPages(), resultPdfDocument, formCopier);
+        }
+
+        Assert.assertNull(new CompareTool().compareByContent(destFilename, cmpFileName, destinationFolder, "diff_"));
+    }
 }