mqtt::connect_options_builder does not work when setting mqtt::properties

[dmf254]

When using mqtt::connect_options_builder::set_properties, the mqtt::connect_options::opts_::connectProperties member is NULL after calling finalize. I believe there's some kind of bug present in the copy constructor/assignment for mqtt::connect_options.

// This does not work (conn_opts1.opts_.connectProperties == NULL)
mqtt::properties conn_props{mqtt::property{mqtt::property::SESSION_EXPIRY_INTERVAL, 600000}};
const auto conn_opts1 = mqtt::connect_options_builder().properties(conn_props).finalize();

// Works
mqtt::connect_options conn_opts2;
conn_opts2.set_properties(conn_props);

// Works
mqtt::connect_options conn_opts3(conn_opts2);

Environment Info:
Microsoft Visual Studio Professional 2022 (64-bit) - LTSC 17.4 (Version 17.4.7)
Windows SDK version 10.0.22000.0 to target Windows 10.0.19045.
MSVC_VERSION 1934 (v143 toolset)

[fpagliughi]

Thanks for reporting this. I think I see what might be missing. First I'd like to try and write a unit test that catches the bug. Then I'll try the fix and and make sure I got it.

[ssams]

I stumbled across the same problem and tried to fix it already, only now also found the issue - definitely an issue in the constructors. PR in #445 should resolve it, let me know if further updates are needed.

[fpagliughi]

I put in a simple unit test to check this, but I did so after I had already merged #445. The unit test is passing, so I will assume that it was #445 that fixed it, and close this.