Horror paths from Corel
Hi everyone,
I'm in desperate situation. I've recieved PDF created in CorelDraw (sic!).
This is what it looks like:

I've tried to connect red lines but I've failed. What I've discovered: every straight line is somehow CLOSED, what it means - it is actually a box built using 2 points! So when I add another point and grab it, object reveals its true nature.
I'll show You in next screenshots what is happenning.
Here: single path selected - status: closed.

On this figure I'm adding one point to it.

On this one the point I've added earlier is grabbed.

And finally after deleting this point path becomes open. Now it can be joined with another one.

My question is - how to convert paths like this into open paths?
Any tips are appreciated!
Best regards
Piotr

