fix: ensure annotations are properly burned after background addition in PDFBurner

EnvelopeGenerator.CommonServices/Jobs/FinalizeDocument/PDFBurner.vb

@@ -51,9 +51,17 @@ Namespace Jobs.FinalizeDocument
         Public Function BurnElementAnnotsToPDF(pSourceBuffer As Byte(), elements As List(Of Signature)) As Byte()
             ' Add background
             Using doc As Pdf(Of MemoryStream, MemoryStream) = Pdf.FromMemory(pSourceBuffer)
-                Return doc.Background(elements).ExportStream().ToArray()
+                pSourceBuffer = doc.Background(elements).ExportStream().ToArray()
-            End Using
 
+                Dim oResult As GdPictureStatus
+                Using oSourceStream As New MemoryStream(pSourceBuffer)
+                    ' Open PDF
+                    oResult = Manager.InitFromStream(oSourceStream)
+                    If oResult <> GdPictureStatus.OK Then
+                        Throw New BurnAnnotationException($"Could not open document for burning: [{oResult}]")
+                    End If
+
+                    'Add annotations
                     For Each element In elements
 
                         Dim x = ToInches(element.Left)
@@ -70,6 +78,19 @@ Namespace Jobs.FinalizeDocument
                         Next
                     Next
 
+                    'Save PDF
+                    Using oNewStream As New MemoryStream()
+                        oResult = Manager.SaveDocumentToPDF(oNewStream)
+                        If oResult <> GdPictureStatus.OK Then
+                            Throw New BurnAnnotationException($"Could not save document to stream: [{oResult}]")
+                        End If
+
+                        Manager.Close()
+
+                        Return oNewStream.ToArray()
+                    End Using
+                End Using
+            End Using
         End Function
 
         Public Function BurnInstantJSONAnnotsToPDF(pSourceBuffer As Byte(), pInstantJSONList As List(Of String)) As Byte()
@@ -192,11 +213,10 @@ Namespace Jobs.FinalizeDocument
         End Sub
 
         Private Sub AddFormFieldValue(name As String, x As Double, y As Double, width As Double, height As Double, page As Integer, value As String)
-
             Dim yOffset As New Dictionary(Of String, Integer) From {
                 {"position", 1},
                 {"date", 2},
-                {"city", 3},
+                {"city", 3}
             }
 
             Manager.SelectPage(page + 1)