I can reproduce this bug every time.
Dolphin->Open Konsole(shift+f4)->Close Konsole.

---------------------------------------------------------------------
Application: kdeinit5 (kdeinit5), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[KCrash Handler]
#6  0x00007fe359aa7abc in ?? () from /usr/lib/x86_64-linux-gnu/libnvidia-glcore.so.340.106
#7  0x00007fe359aa6ccf in ?? () from /usr/lib/x86_64-linux-gnu/libnvidia-glcore.so.340.106
#8  0x00007fe35d34c0a0 in ?? () from /usr/lib/x86_64-linux-gnu/libGL.so.1
#9  0x00007fe360ebf2d3 in ?? () from /lib64/ld-linux-x86-64.so.2
#10 0x00007fe35f0d0831 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#11 0x00007fe35f0d092a in exit () from /lib/x86_64-linux-gnu/libc.so.6
#12 0x0000561d290ce6a4 in ?? ()
#13 0x0000561d290cfc8b in ?? ()
#14 0x0000561d290d051b in ?? ()
#15 0x0000561d290cb00c in ?? ()
#16 0x00007fe35f0baa87 in __libc_start_main () from /lib/x86_64-linux-gnu/libc.so.6
#17 0x0000561d290cbc7a in _start ()
---------------------------------------------------------------------

debian testing
Plasma 5.12.2
Frameworks 5.42
Qt. 5.9.2

Nvidia driver 340.106-2

if dbgsym package are needed please tell me which ones, I will attach a more usefull crash log.

I have used the button in DrKonqi to install debug symbols but that only got me 2 out of 3 stars so I guessed what else could be needed. The backtrace in my report was generated with the following installed (although not all may be needed):
- kinit-dbgsym
- konsole-dbgsym
- libqt5core5a-dbgsym
- libqt5gui5-dbgsym
- libqt5qml5-dbgsym
- libqt5widgets5-dbgsym
- plasma-framework-dbgsym

I'm on KDE Neon User Edition 5.12.3
KDE-Framework 5.43.0
Qt 5.10.0
NVidia driver 384.111

thanks for the reply.
i've tried also with your dbgsym file, but doesn't help.
it seems that mine is a different situation. i've opened another bugreport
bug 391664

I have just had Konsole crash after closing it on my 5.8 system. Interesting how there is a lot of nvidia drivers stuff in this backtrace as well...

System:
 Linux Mint 18.3
 Plasma 5.8.9
 KDE-Framework 5.36.0
 Qt 5.6.1
 NVidia driver 384.111
 Konsole 16.04.3


Application: Konsole (konsole), signal: Aborted
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f23b7a9d940 (LWP 23679))]

Thread 3 (Thread 0x7f23b491e700 (LWP 23681)):
[KCrash Handler]
#6  0x00007f23c9f1f428 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
#7  0x00007f23c9f2102a in __GI_abort () at abort.c:89
#8  0x00007f23c9f617ea in __libc_message (do_abort=do_abort@entry=2, fmt=fmt@entry=0x7f23ca07aed8 "*** Error in `%s': %s: 0x%s ***\n") at ../sysdeps/posix/libc_fatal.c:175
#9  0x00007f23c9f6a37a in malloc_printerr (ar_ptr=<optimized out>, ptr=<optimized out>, str=0x7f23ca07afe8 "double free or corruption (out)", action=3) at malloc.c:5006
#10 _int_free (av=<optimized out>, p=<optimized out>, have_lock=0) at malloc.c:3867
#11 0x00007f23c9f6e53c in __GI___libc_free (mem=<optimized out>) at malloc.c:2968
#12 0x00007f23bd64aae6 in _nv007tls () from /usr/lib/nvidia-384/tls/libnvidia-tls.so.384.111
#13 0x00007f23c2128439 in __nptl_deallocate_tsd () at pthread_create.c:175
#14 0x00007f23c2129870 in __nptl_deallocate_tsd () at pthread_create.c:326
#15 start_thread (arg=0x7f23b491e700) at pthread_create.c:346
#16 0x00007f23c9ff141d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f23b7a99700 (LWP 23680)):
[KCrash Handler]
#5  malloc_consolidate (av=av@entry=0x7f23b0000020) at malloc.c:4169
#6  0x00007f23c9f6bcde in _int_malloc (av=av@entry=0x7f23b0000020, bytes=bytes@entry=2032) at malloc.c:3450
#7  0x00007f23c9f6edca in __libc_calloc (n=<optimized out>, elem_size=<optimized out>) at malloc.c:3236
#8  0x00007f23bd64c3e3 in ?? () from /usr/lib/nvidia-384/tls/libnvidia-tls.so.384.111
#9  0x00007f23c19f5771 in g_malloc0 () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#10 0x00007f23c1a0d2bd in g_slice_free1 () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#11 0x00007f23c2128439 in __nptl_deallocate_tsd () at pthread_create.c:175
#12 0x00007f23c2129870 in __nptl_deallocate_tsd () at pthread_create.c:326
#13 start_thread (arg=0x7f23b7a99700) at pthread_create.c:346
#14 0x00007f23c9ff141d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f23b7a9d940 (LWP 23679)):
#0  0x00007f23bd64ae15 in _nv014tls () from /usr/lib/nvidia-384/tls/libnvidia-tls.so.384.111
#1  0x00007f23c10807cd in ?? () from /usr/lib/nvidia-384/libGL.so.1
#2  0x00007f23c1080bab in ?? () from /usr/lib/nvidia-384/libGL.so.1
#3  0x00007f23c1080c9a in ?? () from /usr/lib/nvidia-384/libGL.so.1
#4  0x00007f23c10c64da in ?? () from /usr/lib/nvidia-384/libGL.so.1
#5  0x00007f23ca509e05 in _dl_fini () at dl-fini.c:240
#6  0x00007f23c9f23ff8 in __run_exit_handlers (status=0, listp=0x7f23ca2ae5f8 <__exit_funcs>, run_list_atexit=run_list_atexit@entry=true) at exit.c:82
#7  0x00007f23c9f24045 in __GI_exit (status=<optimized out>) at exit.c:104
#8  0x00007f23c9f0a837 in __libc_start_main (main=0x4006c0, argc=2, argv=0x7fffb4908bd8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffb4908bc8) at ../csu/libc-start.c:325
#9  0x00000000004006f9 in _start ()

*** This bug has been marked as a duplicate of bug 389272 ***