From 5039da0b91a981b438cbb1c7a7325fde12e2632b Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Fri, 14 Jun 2013 11:27:15 -0400
Subject: [PATCH] Add QPDFObjectHandle::getObjGen()

This is safer than getObjectID() and getGeneration() for many uses.
---
 ChangeLog                        |  4 ++++
 include/qpdf/QPDFObjectHandle.hh | 13 ++++++++++++-
 libqpdf/QPDFObjectHandle.cc      |  6 ++++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 28bf6840..a71b3f18 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2013-06-14  Jay Berkenbilt  <ejb@ql.org>
 
+	* Add new QPDFObjectHandle::getObjGen() method and indiciate in
+	comments that its use is favored over getObjectID() and
+	getGeneration() for most cases.
+
 	* Add new QPDFObjGen object to represent an object ID/generation
 	pair.
 
diff --git a/include/qpdf/QPDFObjectHandle.hh b/include/qpdf/QPDFObjectHandle.hh
index ed02d3bb..81400056 100644
--- a/include/qpdf/QPDFObjectHandle.hh
+++ b/include/qpdf/QPDFObjectHandle.hh
@@ -16,6 +16,7 @@
 #include <set>
 #include <map>
 
+#include <qpdf/QPDFObjGen.hh>
 #include <qpdf/PointerHolder.hh>
 #include <qpdf/Buffer.hh>
 #include <qpdf/InputSource.hh>
@@ -454,7 +455,17 @@ class QPDFObjectHandle
 			   QPDFObjectHandle const& filter,
 			   QPDFObjectHandle const& decode_parms);
 
-    // return 0 for direct objects
+    // Access object ID and generation.  For direct objects, return
+    // object ID 0.
+
+    // NOTE: Be careful about calling getObjectID() and
+    // getGeneration() directly as this can lead to the pattern of
+    // depending on object ID or generation without the other.  In
+    // general, when keeping track of object IDs, it's better to use
+    // QPDFObjGen instead.
+
+    QPDF_DLL
+    QPDFObjGen getObjGen() const;
     QPDF_DLL
     int getObjectID() const;
     QPDF_DLL
diff --git a/libqpdf/QPDFObjectHandle.cc b/libqpdf/QPDFObjectHandle.cc
index 373cd7bd..9a1aae4a 100644
--- a/libqpdf/QPDFObjectHandle.cc
+++ b/libqpdf/QPDFObjectHandle.cc
@@ -535,6 +535,12 @@ QPDFObjectHandle::replaceStreamData(PointerHolder<StreamDataProvider> provider,
 	provider, filter, decode_parms);
 }
 
+QPDFObjGen
+QPDFObjectHandle::getObjGen() const
+{
+    return QPDFObjGen(this->objid, this->generation);
+}
+
 int
 QPDFObjectHandle::getObjectID() const
 {