From 972cbf103da10df7d2dd89313b4ce985a1b06ab8 Mon Sep 17 00:00:00 2001
From: m-holger <m-holger@kubitscheck.org>
Date: Tue, 30 Apr 2024 10:38:59 +0100
Subject: [PATCH] In QPDF::processXRefStream avoid inserting objed id 0 into
 the xref table

---
 libqpdf/QPDF.cc | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index 3f776852..d5e9c7c8 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -1117,8 +1117,7 @@ QPDF::processXRefStream(qpdf_offset_t xref_offset, QPDFObjectHandle& xref_obj)
         if (obj == 0) {
             // This is needed by checkLinearization()
             m->first_xref_item_offset = xref_offset;
-        }
-        if (fields[0] == 0) {
+        } else if (fields[0] == 0) {
             // Ignore fields[2], which we don't care about in this case. This works around the issue
             // of some PDF files that put invalid values, like -1, here for deleted objects.
             insertFreeXrefEntry(QPDFObjGen(obj, 0));