From 07f6c635a95d8c20040896646394c1e5a8a64784 Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Sun, 7 Jan 2024 17:05:35 -0500
Subject: Bug fix: treat old generations of reused objects as null

---
 libqpdf/QPDF.cc | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

(limited to 'libqpdf/QPDF.cc')

diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index 3718eb7e..a089a6c2 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -706,6 +706,19 @@ QPDF::read_xref(qpdf_offset_t xref_offset)
     // We no longer need the deleted_objects table, so go ahead and clear it out to make sure we
     // never depend on its being set.
     m->deleted_objects.clear();
+
+    // Make sure we keep only the highest generation for any object.
+    QPDFObjGen::set to_delete;
+    QPDFObjGen last_og;
+    for (auto const& og: m->xref_table) {
+        if (og.first.getObj() == last_og.getObj()) {
+            to_delete.emplace(last_og);
+        }
+        last_og = og.first;
+    }
+    for (auto const& og: to_delete) {
+        removeObject(og);
+    }
 }
 
 bool
@@ -1978,6 +1991,18 @@ QPDF::replaceObject(QPDFObjGen const& og, QPDFObjectHandle oh)
     updateCache(og, oh.getObj(), -1, -1);
 }
 
+void
+QPDF::removeObject(QPDFObjGen const& og)
+{
+    auto null = QPDFObjectHandle::newNull();
+    m->xref_table.erase(og);
+    if (isCached(og)) {
+        // Take care of any object handles that may be floating around.
+        replaceObject(og, null);
+    }
+    m->obj_cache.erase(og);
+}
+
 void
 QPDF::replaceReserved(QPDFObjectHandle reserved, QPDFObjectHandle replacement)
 {
-- 
cgit v1.2.3-70-g09d2


From 5641832e54e347c2c33e9304d96cca450eb305ed Mon Sep 17 00:00:00 2001
From: m-holger <m-holger@kubitscheck.org>
Date: Mon, 8 Jan 2024 11:43:57 +0000
Subject: Tweak QPDF::read_xref

---
 libqpdf/QPDF.cc | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

(limited to 'libqpdf/QPDF.cc')

diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index a089a6c2..5d09f900 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -708,16 +708,11 @@ QPDF::read_xref(qpdf_offset_t xref_offset)
     m->deleted_objects.clear();
 
     // Make sure we keep only the highest generation for any object.
-    QPDFObjGen::set to_delete;
-    QPDFObjGen last_og;
-    for (auto const& og: m->xref_table) {
-        if (og.first.getObj() == last_og.getObj()) {
-            to_delete.emplace(last_og);
-        }
-        last_og = og.first;
-    }
-    for (auto const& og: to_delete) {
-        removeObject(og);
+    QPDFObjGen last_og{-1, 0};
+    for (auto const& [og, _xref]: m->xref_table) {
+        if (og.getObj() == last_og.getObj())
+            removeObject(last_og);
+        last_og = og;
     }
 }
 
-- 
cgit v1.2.3-70-g09d2


From 8715d6a69389646a1dfd224f618ee6af4e487a1b Mon Sep 17 00:00:00 2001
From: m-holger <m-holger@kubitscheck.org>
Date: Mon, 8 Jan 2024 11:49:21 +0000
Subject: Tweak QPDF::replaceObject

---
 include/qpdf/QPDF.hh |  2 +-
 libqpdf/QPDF.cc      | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

(limited to 'libqpdf/QPDF.cc')

diff --git a/include/qpdf/QPDF.hh b/include/qpdf/QPDF.hh
index 9ab3ae3f..a836c3c9 100644
--- a/include/qpdf/QPDF.hh
+++ b/include/qpdf/QPDF.hh
@@ -1038,7 +1038,7 @@ class QPDF
     QPDFObjectHandle makeIndirectFromQPDFObject(std::shared_ptr<QPDFObject> const& obj);
     bool isCached(QPDFObjGen const& og);
     bool isUnresolved(QPDFObjGen const& og);
-    void removeObject(QPDFObjGen const& og);
+    void removeObject(QPDFObjGen og);
     void updateCache(
         QPDFObjGen const& og,
         std::shared_ptr<QPDFObject> const& object,
diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index 5d09f900..41ecd54a 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -1987,15 +1987,15 @@ QPDF::replaceObject(QPDFObjGen const& og, QPDFObjectHandle oh)
 }
 
 void
-QPDF::removeObject(QPDFObjGen const& og)
+QPDF::removeObject(QPDFObjGen og)
 {
-    auto null = QPDFObjectHandle::newNull();
     m->xref_table.erase(og);
-    if (isCached(og)) {
+    if (auto cached = m->obj_cache.find(og); cached != m->obj_cache.end()) {
         // Take care of any object handles that may be floating around.
-        replaceObject(og, null);
+        cached->second.object->assign(QPDF_Null::create());
+        cached->second.object->setObjGen(nullptr, QPDFObjGen());
+        m->obj_cache.erase(cached);
     }
-    m->obj_cache.erase(og);
 }
 
 void
-- 
cgit v1.2.3-70-g09d2