Digikam crashes when trying to use the Restoration feature in Digikam Image editor.

backtrace:

(gdb) bt
#0  0x00007ffff157e445 in __GI_raise (sig=<optimized out>)
    at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1  0x00007ffff1581bab in __GI_abort () at abort.c:91
#2  0x00007ffff15bbe2e in __libc_message (do_abort=2, 
    fmt=0x7ffff16c40d0 "*** glibc detected *** %s: %s: 0x%s ***\n")
    at ../sysdeps/unix/sysv/linux/libc_fatal.c:201
#3  0x00007ffff15c6626 in malloc_printerr (action=3, 
    str=0x7ffff16c4450 "malloc(): memory corruption (fast)", 
    ptr=<optimized out>) at malloc.c:5007
#4  0x00007ffff15c8e78 in _int_malloc (av=0x7fff90000020, bytes=16)
    at malloc.c:3470
#5  0x00007ffff15caa45 in __GI___libc_malloc (bytes=16) at malloc.c:2924
#6  0x00007ffff252153c in queued_activate (argv=0x7fffa73a8ae0, c=0x3eb1a80, 
    signal=11, sender=0x4142220) at kernel/qobject.cpp:3421
#7  QMetaObject::activate (sender=0x4142220, m=<optimized out>, 
    local_signal_index=<optimized out>, argv=0x7fffa73a8ae0)
    at kernel/qobject.cpp:3507
#8  0x00007ffff565b782 in Digikam::DImgThreadedFilter::finished (
    this=<optimized out>, _t1=true)
    at /tmp/buildd/digikam-2.6.0/obj-x86_64-linux-gnu/core/digikam/dimgthreadedfilter.moc:117
#9  0x00007ffff565b8cf in Digikam::DImgThreadedFilter::startFilterDirectly (
    this=0x4142220)
    at /tmp/buildd/digikam-2.6.0/core/libs/dimg/filters/dimgthreadedfilter.cpp:199
#10 0x00007ffff58239ce in Digikam::DynamicThread::DynamicThreadPriv::run (
    this=0x3d9bd00)
    at /tmp/buildd/digikam-2.6.0/core/libs/threads/dynamicthread.cpp:186
#11 0x00007ffff24014f2 in QThreadPoolThread::run (this=0x25ff0f0)
    at concurrent/qthreadpool.cpp:107
#12 0x00007ffff240dfcb in QThreadPrivate::start (arg=0x25ff0f0)
    at thread/qthread_unix.cpp:298
#13 0x00007fffece30e9a in start_thread (arg=0x7fffa73a9700)
---Type <return> to continue, or q <return> to quit---
    at pthread_create.c:308
#14 0x00007ffff163a4bd in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#15 0x0000000000000000 in ?? ()


Reproducible: Always

Steps to Reproduce:
1.Open an image for edit in Digikams Image editor.
2.Select Enhance > Restoration
3.If no restoration effect try to apply to the image select a Filtering typ and press "try" to make the calculation.
4. The restoration progress bar crashes around at 93% every time.
Actual Results:  
Digikam crashes

Expected Results:  
Restoration filter applys without crash.