After setting ddd then gdb option, then closing, ddd hangs on next invokation

[Tim Tautges]

I perform the following with ddd, with no existing $HOME/.ddd directory:

1. run ddd (no executable specified); close banner & other popup window

2. in ddd, Edit->Preferences, Source tab, select Display Source Line Numbers, 
then select Ok

3. in ddd, Edit->GDB Settings, scroll down to Printing of C++ static members, 
de-select, then Close

4. quit ddd

5. start ddd; debugger hangs; shows 'Opening session "..."' at bottom

I'm attaching two log files; log1 contains log of first session, log2 of second 
(after killing ddd)

I'm running ddd 3.3.12 on a CentOS 7 system.

log1
Description: Text document

log2
Description: Text document