Thanks Mirza,
I have a few extra comments which may be helpful, or a nuisance.
1) When I first choose the Join Polyline button, the command line asks me to:
> PLINEJOIN
Select polyline
In my previous comments I suggested that after this command appears and I then click on one of the polylines it becomes selected, even though it does not change to dotted line.
This is not correct - I now notice that when I click on a polyline to select it the properties box shows "Nothing Selected". However the command line assumes that a selection has been made and displays the next command:
Specify other lines/polylines/arcs to join
Thus, although it appears in the command line that the first polyline has been selected and a second or subsequent polyline should now be selected, in fact clicking on a polyline at this point makes the first selection. In other words the command line and selection actions are now out of step.
Once you realise this it is easy but not intuitive to select a subsequent polyline. On the other hand if you don't notice this misstep and assume you have selected both then press enter it is disconcerting to find that one polyline may sometimes disappear never to return.
2) It certainly makes sense to have the objects close to one another to join them in fact I am now finding that it is virtually necessary for 2 polylines to be touching at existing vertices to create a reliable join. I have observed the disappearing polyline phenomenon even when one end of an open polyline (like the W shapes I was creating yesterday) is actually in contact with a non-vertex point of a closed shape like a rectangle (joining these often results in the disappearance of the W shape).
3) I realise that you have said there is a need to fix the joining of straight line segmented polylines and arcs (presumably including ellipses and circles. So this is anecdotal but I found it to be of interest. I tried joining a straight line segmented polyline to a circle. Regardless of the size of the polyline and circle, and their positions, joining them consistently results in them both disappearing and being replaced with a single straight line from the origin to the centre of the circle. This is similar to the phenomenon I observed yesterday where joining a polyline and an arc resulted in the polyline replacing the arc between its two end points.
I guess its related to the algorithm in place to join dissimilar vector paths.
I hope that may have been useful but I will abandon experiments with polyline until your next release.
On an unrelated note. You probably noticed I had changed my background from black to white. I have just noticed that regardless of whether the GRID button is on or off there is no grid for the white background. I choose the white background as it is better for my eyes since I have poor contrast sensitivity (comes partly with old age - I will be 67 soon).
Finally, as BabaCAD is graphical software , it would be useful to me at least, and possibly others, if the ability to attach files to forum posts was turned on for members. Then we could attach screenshots, or even short videos, to support our comments. While I can continue to use linked documents from my Google drive others may not have that capacity
Kind regards,
Paul