From 742190bd98c0981a07cb39a8eae1e99d909ad5ae Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Tue, 29 Aug 2017 12:27:44 -0400
Subject: [PATCH] Pl_PNGFilter: disallow columns = 0

---
 libqpdf/Pl_PNGFilter.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libqpdf/Pl_PNGFilter.cc b/libqpdf/Pl_PNGFilter.cc
index 4b79e6b1..1566c8a5 100644
--- a/libqpdf/Pl_PNGFilter.cc
+++ b/libqpdf/Pl_PNGFilter.cc
@@ -14,6 +14,10 @@ Pl_PNGFilter::Pl_PNGFilter(char const* identifier, Pipeline* next,
     buf2(0),
     pos(0)
 {
+    if (columns == 0)
+    {
+        throw std::runtime_error("PNGFilter created with columns = 0");
+    }
     this->buf1 = new unsigned char[columns + 1];
     this->buf2 = new unsigned char[columns + 1];
     this->cur_row = buf1;