From ec6719fd25ebd49c43142a607353bad5df7874aa Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Thu, 25 Feb 2021 05:38:52 -0500
Subject: [PATCH] Always call dereference() before querying obj pointer

---
 libqpdf/QPDFObjectHandle.cc | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/libqpdf/QPDFObjectHandle.cc b/libqpdf/QPDFObjectHandle.cc
index 3a7bb2f9..c650bdea 100644
--- a/libqpdf/QPDFObjectHandle.cc
+++ b/libqpdf/QPDFObjectHandle.cc
@@ -326,6 +326,8 @@ QPDFObjectHandle::isBool()
 bool
 QPDFObjectHandle::isDirectNull() const
 {
+    // Don't call dereference() -- this is a const method, and we know
+    // objid == 0, so there's nothing to resolve.
     return (this->initialized && (this->objid == 0) &&
             QPDFObjectTypeAccessor<QPDF_Null>::check(obj.getPointer()));
 }
@@ -2452,6 +2454,8 @@ QPDFObjectHandle::getParsedOffset()
 void
 QPDFObjectHandle::setParsedOffset(qpdf_offset_t offset)
 {
+    // This is called during parsing on newly created direct objects,
+    // so we can't call dereference() here.
     if (this->obj.getPointer())
     {
         this->obj->setParsedOffset(offset);
@@ -2694,6 +2698,8 @@ void
 QPDFObjectHandle::setObjectDescription(QPDF* owning_qpdf,
                                        std::string const& object_description)
 {
+    // This is called during parsing on newly created direct objects,
+    // so we can't call dereference() here.
     if (isInitialized() && this->obj.getPointer())
     {
         this->obj->setDescription(owning_qpdf, object_description);
@@ -2703,9 +2709,13 @@ QPDFObjectHandle::setObjectDescription(QPDF* owning_qpdf,
 bool
 QPDFObjectHandle::hasObjectDescription()
 {
-    if (isInitialized() && this->obj.getPointer())
+    if (isInitialized())
     {
-        return this->obj->hasDescription();
+        dereference();
+        if (this->obj.getPointer())
+        {
+            return this->obj->hasDescription();
+        }
     }
     return false;
 }