Repeatedly opening file from Recent-pane and immediate Close leaks a bit memory

Testing open mp4-file from Recent-pane and then immediate close (Ctrl-W).

Fedora 29 flatpak-build: v18.11.18

I see the RssAnon/VmData field increasing for each open/close-cycle.

[henning@satellite ~]$ cat /proc/$(pgrep shotcut)/status
Name:	shotcut
Umask:	0002
State:	S (sleeping)
Tgid:	9106
Ngid:	0
Pid:	9106
PPid:	9105
TracerPid:	0
Uid:	1000	1000	1000	1000
Gid:	1001	1001	1001	1001
FDSize:	64
Groups:	10 975 1000 1001 1002 1003 
NStgid:	9106	2
NSpid:	9106	2
NSpgid:	9096	0
NSsid:	2065	0
VmPeak:	 2951904 kB
VmSize:	 2742156 kB
VmLck:	       0 kB
VmPin:	       0 kB
VmHWM:	  365344 kB
VmRSS:	  358556 kB
RssAnon:	  260100 kB
RssFile:	   89184 kB
RssShmem:	    9272 kB
VmData:	  535040 kB
VmStk:	     136 kB
VmExe:	    2764 kB
VmLib:	  197088 kB
VmPTE:	    1900 kB
VmSwap:	       0 kB
HugetlbPages:	       0 kB
CoreDumping:	0
Threads:	14
SigQ:	0/23119
SigPnd:	0000000000000000
ShdPnd:	0000000000000000
SigBlk:	0000000000000000
SigIgn:	0000000000001000
SigCgt:	0000000180000000
CapInh:	0000000000000000
CapPrm:	0000000000000000
CapEff:	0000000000000000
CapBnd:	0000000000000000
CapAmb:	0000000000000000
NoNewPrivs:	1
Seccomp:	2
Speculation_Store_Bypass:	thread force mitigated
Cpus_allowed:	ff
Cpus_allowed_list:	0-7
Mems_allowed:	00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000001
Mems_allowed_list:	0
voluntary_ctxt_switches:	45700
nonvoluntary_ctxt_switches:	23991
`

I also see two Audio Opnened during close in the app log.

`[Debug  ] <MainWindow::open> "/home/henning/Nedlastinger/test.mp4" 
[Debug  ] <MltXmlChecker::MltXmlChecker> decimal point ',' 
[Debug  ] <MltXmlChecker::check> begin 
[Debug  ] <MltXmlChecker::check> end 
[Debug  ] <MLT> [producer avformat] "/home/henning/Nedlastinger/test.mp4" checking VFR: pkt.duration 512
[swscaler @ 0x88ab700] YUV color matrix differs for YUV->YUV, using intermediate RGB to convert
[Debug  ] <MainWindow::setAudioChannels> 1 
[Debug  ] <Mlt::Controller::setAudioChannels> 1 
[Info   ] <MainWindow::open> "/home/henning/Nedlastinger/test.mp4" 
[Info   ] <MLT> [consumer sdl2_audio] Audio Opened: driver=pulseaudio channels=1 frequency=48000


[Debug  ] <MainWindow::on_actionClose_triggered>  
[Debug  ] <Mlt::Controller::setProjectFolder> project folder "" 
[Debug  ] <MainWindow::setAudioChannels> 1 
[Debug  ] <Mlt::Controller::setAudioChannels> 1 
[Info   ] <MLT> [consumer sdl2_audio] Audio Opened: driver=pulseaudio channels=1 frequency=48000
[Info   ] <MLT> [consumer sdl2_audio] Audio Opened: driver=pulseaudio channels=1 frequency=48000
[Debug  ] <MainWindow::setProfile> "" 
[Debug  ] <Mlt::Controller::setProfile> setting to profile "Automatic" 
`

Reproduce the issue by opening an MP4 from the Recent pane and immediately pressing Ctrl-W, then compare RssAnon/VmData in /proc status and review the application log. Investigate the close path associated with MainWindow::on_actionClose_triggered and the repeated Audio Opened messages. Done means repeated open/close cycles no longer show unbounded memory growth or duplicate audio openings.