xpdf crashes if /etc/papersize is invalid

[Gregory James Duck]

The default contents of /etc/papersize on my system is "a4".

However, if /etc/papersize is replaced with "aa4", then xpdf will crash on launch.

The problem appears to be a basic NULL pointer dereference in XPDFParams.cc:

    paperType = paperinfo(paperName);
    psPaperWidth = (int)paperpswidth(paperType);

Here, paperinfo("aa4") returns NULL, which is not checked before it is dereferenced by paperpswidth().

ProblemType: Bug
DistroRelease: Ubuntu 23.04
Package: xpdf 3.04+git20220601-1build2
ProcVersionSignature: Ubuntu 6.2.0-20.20-generic 6.2.6
Uname: Linux 6.2.0-20-generic x86_64
ApportVersion: 2.26.1-0ubuntu2
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Mon Jun 19 14:29:34 2023
InstallationDate: Installed on 2023-05-30 (20 days ago)
InstallationMedia: Ubuntu 23.04 "Lunar Lobster" - Release amd64 (20230418)
ProcEnviron:
 LANG=en_US.UTF-8
 PATH=(custom, no user)
 SHELL=/bin/bash
 TERM=xterm-256color
 XDG_RUNTIME_DIR=<set>
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: xpdf
UpgradeStatus: No upgrade log present (probably fresh install)