After closing Konqueror (not just opened, some surfing have to be done) it process still exists. Happens not every time, but almost every if at least some surfing was done. I'm using webkit engine. Can't reproduce with khtml. Right after closing memory consuption is decreased, but not to "zero", stop at 100MiB+.

Reproducible: Sometimes

Steps to Reproduce:
1. Use webkit engine as default.
2. Open Konqueror, open some tabs, follow the links, close some tabs. So, usual surfing.
3. Close Konqueror (Ctrl+Q or press close button — doesn't matter).
Actual Results:  
pgrep konqueror / ps / krunner — process still here.

Expected Results:  
Process should be terminated after a while.

Attaching gdb doesn't provide helpful info:
(gdb) info threads
  Id   Target Id         Frame 
* 1    process 4233 "konqueror" 0x00007fcd7205fb3d in ?? ()
(gdb) bt
#0  0x00007fcd7205fb3d in ?? ()
#1  0x0000000000000000 in ?? ()