[BUG] Random crash on startup - possible race condition

[smac89]

I noticed that sometimes when I open this tool from the applications menu, it wouldn't open, yet other times it does.

I decided to test it on the command line, and here are the results of opening the application 6 times:

➜ sddm-conf       
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4636
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4592
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4247

~ took 28s 
➜ sddm-conf
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4636
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4592
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4247
terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc
[1]    325120 IOT instruction (core dumped)  sddm-conf

~ 
✖ sddm-conf
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4636
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4592
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4247

~ took 2s 
➜ sddm-conf
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4636
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4592
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4247
terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc
[1]    325832 IOT instruction (core dumped)  sddm-conf

~ 
✖ sddm-conf
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4636
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4592
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4247
terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc
[1]    325884 IOT instruction (core dumped)  sddm-conf

~ 
✖ sddm-conf
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4636
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4592
qt.svg: <input>:1646:6: Could not resolve property: #linearGradient4247

As you can see, out of 6 times, it only opened properly 3 times, and the occurrence of the crash doesn't seem to be consistent, nor do we get any extra messages printed before it occurs.