Posted by ravas on Mar 14, 2016; 11:24pm
URL: https://forum.librecad.org/Polyline-Create-Polyline-from-Existing-Segments-tp5713306p5713309.html

Actually it does work;
however, the lines are not highlighted (this is a bug).

I recommend that you first select all the lines you want to convert, and then select the tool.
In this order, selecting the tool finalizes the operation.