Bug#909632: pngmeta: segfault on bad png

[Kevin Ryde <user42_kevin@yahoo.com.au>]

Package: pngmeta
Version: 1.11-9
Severity: normal
File: /usr/bin/pngmeta

With file https://www.gutenberg.org/files/16713/16713-h/images/q248.png
(about 7 kbytes), running "pngmeta q248.png" gets a segfault.

I suspect some badness in that image, since some other programs don't
enjoy it either (xzgv "can't load", dillo "checksum error"), but I hoped
pngmeta would not segfault.

gdb gives a backtrace showing somewhere under the final
png_destroy_read_struct() call in pngmeta.c main().

    #0  0xb7f8367a in png_free_data () from /usr/lib/i386-linux-gnu/libpng16.so.16
    #1  0xb7f83ce2 in png_destroy_info_struct ()
       from /usr/lib/i386-linux-gnu/libpng16.so.16
    #2  0xb7f9022d in png_destroy_read_struct ()
       from /usr/lib/i386-linux-gnu/libpng16.so.16
    #3  0x80001b39 in main (argc=<optimized out>, argv=<optimized out>)
        at pngmeta.c:588


-- System Information:
Debian Release: buster/sid
Architecture: i386 (i686)

Kernel: Linux 4.4.0-1-686-pae (SMP w/1 CPU core)
Locale: LANG=en_AU.iso88591, LC_CTYPE=en_AU.iso88591 (charmap=ISO-8859-1), LANGUAGE=en_AU:en_GB:en (charmap=ISO-8859-1)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages pngmeta depends on:
ii  libc6        2.27-6
ii  libpng16-16  1.6.34-2
ii  zlib1g       1:1.2.11.dfsg-1

pngmeta recommends no packages.

pngmeta suggests no packages.

-- no debconf information