Add class QPDF_Unresolved

Allow QPDFObjectHandle::obj to be set prior resolving object.

ot_unresolved has been appended to the list object types in order to
preserve the output of existing test cases.

include/qpdf/Constants.h

@@ -82,6 +82,8 @@ enum qpdf_object_type_e {
     /* Additional object types that can occur in content streams */
     ot_operator,
     ot_inlineimage,
+    /* Object types internal to qpdf */
+    ot_unresolved,
     /* NOTE: if adding to this list, update QPDFObject.hh */
 };
 

include/qpdf/QPDFObject.hh

@@ -61,6 +61,7 @@ class QPDFObject
     static constexpr object_type_e ot_stream = ::ot_stream;
     static constexpr object_type_e ot_operator = ::ot_operator;
     static constexpr object_type_e ot_inlineimage = ::ot_inlineimage;
+    static constexpr object_type_e ot_unresolved = ::ot_unresolved;
 
     virtual ~QPDFObject() = default;
     virtual std::shared_ptr<QPDFObject> shallowCopy() = 0;

libqpdf/CMakeLists.txt

@@ -99,6 +99,7 @@ set(libqpdf_SOURCES
   QPDF_Reserved.cc
   QPDF_Stream.cc
   QPDF_String.cc
+  QPDF_Unresolved.cc
   QPDF_encryption.cc
   QPDF_json.cc
   QPDF_linearization.cc

libqpdf/QPDF_Unresolved.cc

@@ -0,0 +1,41 @@
+#include <qpdf/QPDF_Unresolved.hh>
+
+#include <stdexcept>
+
+std::shared_ptr<QPDFObject>
+QPDF_Unresolved::create()
+{
+    return do_create(new QPDF_Unresolved());
+}
+
+std::shared_ptr<QPDFObject>
+QPDF_Unresolved::shallowCopy()
+{
+    return create();
+}
+
+std::string
+QPDF_Unresolved::unparse()
+{
+    throw std::logic_error(
+        "attempted to unparse an unresolveded QPDFObjectHandle");
+    return "";
+}
+
+JSON
+QPDF_Unresolved::getJSON(int json_version)
+{
+    return JSON::makeNull();
+}
+
+QPDFObject::object_type_e
+QPDF_Unresolved::getTypeCode() const
+{
+    return QPDFObject::ot_unresolved;
+}
+
+char const*
+QPDF_Unresolved::getTypeName() const
+{
+    return "unresolved";
+}

libqpdf/qpdf/QPDF_Unresolved.hh

@@ -0,0 +1,21 @@
+#ifndef QPDF_UNRESOLVED_HH
+#define QPDF_UNRESOLVED_HH
+
+#include <qpdf/QPDFObject.hh>
+
+class QPDF_Unresolved: public QPDFObject
+{
+  public:
+    virtual ~QPDF_Unresolved() = default;
+    static std::shared_ptr<QPDFObject> create();
+    virtual std::shared_ptr<QPDFObject> shallowCopy();
+    virtual std::string unparse();
+    virtual JSON getJSON(int json_version);
+    virtual QPDFObject::object_type_e getTypeCode() const;
+    virtual char const* getTypeName() const;
+
+  private:
+    QPDF_Unresolved() = default;
+};
+
+#endif // QPDF_UNRESOLVED_HH