Description of problem:

See https://trac.videolan.org/vlc/ticket/20418#ticket :



With this file that I obtained using youtube-dl - ​http://www.shlomifish.org/Files/files/video/Yeah%20Boy%20by%20Kelsea%20Ballerini%20Cover%20by%20Victoria%20Avenue-W3Khu92THiI.webm

vlc segfaults sometimes after invoking it from the cmdline. I am on mageia v7 x64 using xfce and vlc git master

commit 73d1c4accf99855f476cbf0e90337061aebc5949
Author: Rémi Denis-Courmont <remi@remlab.net>
Date:   Fri May 4 15:11:48 2018 +0300

    aout: relax memory ordering for stats

diff --git a/src/audio_output/dec.c b/src/audio_output/dec.c
index 8bd3ded8fa..afb38ff5dc 100644

here is the gdb session log: 

Thread 15 (Thread 0x7fffe9d2d700 (LWP 21742)):
#0  0x00007fffe6b7d263 in  () at /lib64/libGL.so.1
#1  0x00007fffe6b7d3be in  () at /lib64/libGL.so.1
#2  0x00007fffe83a2c12 in XCloseDisplay (dpy=0x7fffc400e020) at ClDisplay.c:65
        ext = 0x7fffc4362440
        i = <optimized out>
#3  0x00007fffe826b924 in QXcbConnection::~QXcbConnection() ()
    at /lib64/libQt5XcbQpa.so.5
#4  0x00007fffe826b9c9 in QXcbConnection::~QXcbConnection() ()
    at /lib64/libQt5XcbQpa.so.5
#5  0x00007fffe826d546 in QXcbIntegration::~QXcbIntegration() ()
    at /lib64/libQt5XcbQpa.so.5
#6  0x00007fffe826d649 in QXcbIntegration::~QXcbIntegration() ()
    at /lib64/libQt5XcbQpa.so.5
#7  0x00007fffe763d48d in QGuiApplicationPrivate::~QGuiApplicationPrivate() ()
    at /lib64/libQt5Gui.so.5
#8  0x00007fffe881f1a9 in QApplicationPrivate::~QApplicationPrivate() ()
    at /lib64/libQt5Widgets.so.5
#9  0x00007fffe729f996 in QObject::~QObject() () at /lib64/libQt5Core.so.5
#10 0x00007fffe726cba8 in QCoreApplication::~QCoreApplication() ()
    at /lib64/libQt5Core.so.5
#11 0x00007fffe8821139 in QApplication::~QApplication() ()
    at /lib64/libQt5Widgets.so.5
#12 0x00007fffe8d7f16c in QVLCApp::~QVLCApp() (this=0x7fffe9d2ce10, __in_chrg=<optimized out>) at gui/qt/util/qvlcapp.hpp:37
        p_intf = 0x6ff080
        p_sys = 0x712220
        vlc_name = "vlc"
        argv = {0x7fffe9d2ce54 "vlc", 0x0}

Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
1. Invoke vlc from the terminal with a .webm file.
2. Hit next track a few times.
3. exit using ctrl+q
4. sometimes it segfaults.