Bug#811385: adplay: ftbfs with gcc-6

[Trevor Saunders <trev.saunders@gmail.com>]

Package: adplay
Severity: normal
Tags: upstream
Usertags: ftbfs-gcc-6

Dear Maintainer,

adplay fails to build with gcc 6 because adplay.cc:92 tries to
initialize cfg.subsong which is an unsigned int with -1 which is invalid
in C++11.

The error from gcc is:

adplay.cc:98:1: error: narrowing conversion of '-1' from 'int' to
'unsigned int' inside { } [-Wnarrowing]
 };
  ^

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.3.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_CA.UTF-8, LC_CTYPE=en_CA.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)