guix/gnu/packages/patches/p7zip-CVE-2016-9296.patch

From: Robert Luberda <robert@debian.org>
Date: Sat, 19 Nov 2016 08:48:08 +0100
Subject: Fix nullptr dereference (CVE-2016-9296)

Patch taken from https://sourceforge.net/p/p7zip/bugs/185/
This patch file taken from Debian's patch set for p7zip
---
 CPP/7zip/Archive/7z/7zIn.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/CPP/7zip/Archive/7z/7zIn.cpp b/CPP/7zip/Archive/7z/7zIn.cpp
index b0c6b98..7c6dde2 100644
--- a/CPP/7zip/Archive/7z/7zIn.cpp
+++ b/CPP/7zip/Archive/7z/7zIn.cpp
@@ -1097,7 +1097,8 @@ HRESULT CInArchive::ReadAndDecodePackedStreams(
       if (CrcCalc(data, unpackSize) != folders.FolderCRCs.Vals[i])
         ThrowIncorrect();
   }
-  HeadersSize += folders.PackPositions[folders.NumPackStreams];
+  if (folders.PackPositions)
+      HeadersSize += folders.PackPositions[folders.NumPackStreams];
   return S_OK;
 }