Merge pull request #1014 from m-holger/i1011

Change QPDF::copyForeignObject to return a null object when called wi…

Merge pull request #1014 from m-holger/i1011
Change QPDF::copyForeignObject to return a null object when called wi…
Jay Berkenbilt · GitHub
2 parents fec75b44 b0c3ea2b
Showing 3 changed files with 11 additions and 6 deletions
libqpdf/QPDF.cc
qpdf/qtest/qpdf/copy-foreign-objects-25.out
qpdf/test_driver.cc
@@ -2034,13 +2034,13 @@ QPDF::copyForeignObject(QPDFObjectHandle foreign)
     }
     obj_copier.to_copy.clear();
-    auto& result = obj_copier.object_map[foreign.getObjGen()];
-    if (!result.isInitialized()) {
-        result = QPDFObjectHandle::newNull();
-        warn(damagedPDF("Unexpected reference to /Pages object while copying foreign object. "
-                        "Replacing with Null object."));
+    auto og = foreign.getObjGen();
+    if (!obj_copier.object_map.count(og)) {
+        warn(damagedPDF("unexpected reference to /Pages object while copying foreign object; "
+                        "replacing with null"));
+        return QPDFObjectHandle::newNull();
     }
-    return result;
+    return obj_copier.object_map[foreign.getObjGen()];
 }
 void
+WARNING: minimal.pdf (object 6 0, offset 556): unexpected reference to /Pages object while copying foreign object; replacing with null
 test 25 done
@@ -954,6 +954,8 @@ test_25(QPDF&amp; pdf, char const* arg2)
     // Copy qtest without crossing page boundaries.  Should get O1
     // and O2 and their streams but not O3 or any other pages.
+    // Also verify that attempts to copy /Pages objects return null.
+
     assert(arg2 != nullptr);
     {
         // Make sure original PDF is out of scope when we write.
@@ -961,6 +963,8 @@ test_25(QPDF&amp; pdf, char const* arg2)
         oldpdf.processFile(arg2);
         QPDFObjectHandle qtest = oldpdf.getTrailer().getKey("/QTest");
         pdf.getTrailer().replaceKey("/QTest", pdf.copyForeignObject(qtest));
+
+        assert(pdf.copyForeignObject(oldpdf.getRoot().getKey("/Pages")).isNull());
     }
     QPDFWriter w(pdf, "a.pdf");