From c6179da9615057a14e74180f640e2e77fdcbf234 Mon Sep 17 00:00:00 2001
From: m-holger <m-holger@kubitscheck.org>
Date: Thu, 17 Nov 2022 17:35:13 +0000
Subject: Add new method QPDFValue::checkOwnership

---
 libqpdf/QPDF_Array.cc      | 20 ++++++++++++++++++++
 libqpdf/qpdf/QPDF_Array.hh |  3 +++
 2 files changed, 23 insertions(+)

diff --git a/libqpdf/QPDF_Array.cc b/libqpdf/QPDF_Array.cc
index e9d216a5..def40e9b 100644
--- a/libqpdf/QPDF_Array.cc
+++ b/libqpdf/QPDF_Array.cc
@@ -7,6 +7,26 @@
 
 static const QPDFObjectHandle null_oh = QPDFObjectHandle::newNull();
 
+inline void
+QPDF_Array::checkOwnership(QPDFObjectHandle const& item) const
+{
+    if (auto obj = item.getObjectPtr()) {
+        if (qpdf) {
+            if (auto item_qpdf = obj->getQPDF()) {
+                if (qpdf != item_qpdf) {
+                    throw std::logic_error(
+                        "Attempting to add an object from a different QPDF. "
+                        "Use QPDF::copyForeignObject to add objects from "
+                        "another file.");
+                }
+            }
+        }
+    } else {
+        throw std::logic_error(
+            "Attempting to add an uninitialized object to a QPDF_Array.");
+    }
+}
+
 QPDF_Array::QPDF_Array(std::vector<QPDFObjectHandle> const& v) :
     QPDFValue(::ot_array, "array")
 {
diff --git a/libqpdf/qpdf/QPDF_Array.hh b/libqpdf/qpdf/QPDF_Array.hh
index 4947d09c..b27ce122 100644
--- a/libqpdf/qpdf/QPDF_Array.hh
+++ b/libqpdf/qpdf/QPDF_Array.hh
@@ -42,6 +42,9 @@ class QPDF_Array: public QPDFValue
     QPDF_Array(std::vector<std::shared_ptr<QPDFObject>>&& items, bool sparse);
     QPDF_Array(SparseOHArray const& items);
     QPDF_Array(std::vector<std::shared_ptr<QPDFObject>> const& items);
+
+    void checkOwnership(QPDFObjectHandle const& item) const;
+
     bool sparse{false};
     SparseOHArray sp_elements;
     std::vector<std::shared_ptr<QPDFObject>> elements;
-- 
cgit v1.2.3-54-g00ecf