Description of problem:
Dunst hangs if a notification is displayed and DUNST_COMMAND_PAUSE is received.

Version-Release number of selected component (if applicable):
dunst-1.0.0-5.fc21.x86_64

How reproducible:
100 %

Steps to Reproduce:
1. Let dunst to display a message: $ notify-send test
2. While the message is shown, try to pause dunst: $ notify-send DUNST_COMMAND_PAUSE

Actual results:
CPU usage rockets to 100 %

Expected results:
Well, at lest the CPU should not be eaten by dunst :-) I'm not sure if currently displayed message should be displayed until RESUME or if PAUSE should just hold new messages and let old message disappear.


Additional info:
(gdb) thread apply all bt

Thread 2 (Thread 0x7fa5eebef980 (LWP 10919)):
#0  allocator_categorize (aligned_chunk_size=32) at gslice.c:460
#1  g_slice_free1 (mem_size=mem_size@entry=24, mem_block=0x2602060) at gslice.c:1080
#2  0x00007fa5ec9827ed in g_list_free_1 (list=<optimized out>) at glist.c:200
#3  0x00007fa5ec9976c2 in g_queue_pop_head (queue=0x2602040) at gqueue.c:521
#4  0x00000000004061d4 in update_lists () at dunst.c:108
#5  0x00000000004062b8 in run (data=0x0) at dunst.c:235
#6  0x0000000000406873 in onNotify (invocation=0x7fa5d0003090, parameters=0x7864ccb294db3d00, sender=0x7fa5d0012200 ":1.120", connection=0x260c030) at dbus.c:281
#7  handle_method_call (connection=0x260c030, sender=sender@entry=0x7fa5d0012200 ":1.120", object_path=object_path@entry=0x7fa5d000e9d0 "/org/freedesktop/Notifications", 
    interface_name=interface_name@entry=0x7fa5d0002d70 "org.freedesktop.Notifications", method_name=method_name@entry=0x7fa5d0010cb0 "Notify", 
    parameters=parameters@entry=0x7fa5d0012aa0, invocation=0x7fa5d0003090, user_data=0x0) at dbus.c:84
#8  0x00007fa5ed3ea9dc in call_in_idle_cb (user_data=0x7fa5d0003090) at gdbusconnection.c:4884
#9  0x00007fa5ec986aeb in g_main_dispatch (context=0x2602a30) at gmain.c:3111
#10 g_main_context_dispatch (context=context@entry=0x2602a30) at gmain.c:3710
#11 0x00007fa5ec986e88 in g_main_context_iterate (context=0x2602a30, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3781
#12 0x00007fa5ec9871b2 in g_main_loop_run (loop=0x262a550) at gmain.c:3975
#13 0x000000000040407c in main (argc=<optimized out>, argv=<optimized out>) at dunst.c:347

Thread 1 (Thread 0x7fa5df424700 (LWP 10921)):
#0  0x00007fa5ebf481dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fa5ec986e24 in g_main_context_poll (priority=2147483647, n_fds=2, fds=0x7fa5d00010c0, timeout=-1, context=0x7fa5d800e4a0) at gmain.c:4076
#2  g_main_context_iterate (context=0x7fa5d800e4a0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3776
#3  0x00007fa5ec9871b2 in g_main_loop_run (loop=0x7fa5d800e430) at gmain.c:3975
#4  0x00007fa5ed3f9d96 in gdbus_shared_thread_func (user_data=0x7fa5d800e470) at gdbusprivate.c:273
#5  0x00007fa5ec9ad7b5 in g_thread_proxy (data=0x260e6d0) at gthread.c:764
#6  0x00007fa5ec21752a in start_thread (arg=0x7fa5df424700) at pthread_create.c:310
#7  0x00007fa5ebf5377d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

It seems that it is looping in while loop here:
(gdb) frame
#4  0x00000000004061d4 in update_lists () at dunst.c:108
108	                        g_queue_insert_sorted(queue, g_queue_pop_head(queue),
(gdb) l
103	
104	        check_timeouts();
105	
106	        if (pause_display) {
107	                while (displayed->length > 0) {
108	                        g_queue_insert_sorted(queue, g_queue_pop_head(queue),
109	                                              notification_cmp_data, NULL);
110	                }
111	                return;
112	        }

I'm not sure what is the purpose of this code.