Close line bug?

li
0,0
100,0
@0,50
c

The command above creates 2 acmes of a triangle. Then with 'c' close triangle.
LibreCAD says (equivalent from my language) "Not possible to close because not enough entities or already closed".

This bug existed in earlier versions of AutoCAD, but not in AutoCAD 2020.
It is so clear: "enough entities" are 2. Not 3.

li is the command for 2-point line entities.
Even when one can create a couple of lines in sequence, this is only for comfort.
In the end all lines are separate entities. There is no relation between the lines which is necessary to recognize a triangle or any other shape.

The close command is for polylines and for them it works for me.
These commands create a triangle for me:
pl
0,0
@100,0
@0,50
c

So the trick is to use pl (polyline) instead of li (2-point line).

Your answer does not explain why the following works. (3 consecutive segments instead of 2)

li
0,0
100,0
@0,50
@-50,0
c

So, If with 3 consecutive line segments CAN close the line, I believe the correct number of needed segments are 2.

Polyline has nothing to do with what I say. I need consecutive line segments, not a polyline.
I do not want to make a triangle with polyline. I give an example.

Please read carefully:
IF you create 2 consecutive segments with LI, you can CLOSE the 2 segments with one more. But LibreCAD disagree. Because LibraCAD counts 3 segments to allow this. It must count 2 segments.

chameleon wrote

...

Please read carefully:
IF you create 2 consecutive segments with LI, you can CLOSE the 2 segments with one more. But LibreCAD disagree. Because LibraCAD counts 3 segments to allow this. It must count 2 segments.

Chameleon is correct.  It seems that a minimum of three segments are required for "Close" to work when using the 2pt line tool.  With two segments, the command line output shows an error: "Cannot close sequence of lines: Not enough entities defined yet, or already closed."  When drawing three segments using the 2pt line tool,  a fourth segment is created when "Close" is clicked and a four-sided polygon is created.

Creating a rectangle will work:

li
0,0
50,0
50,25
0,25
c

Creating a triangle will not work:

li
0,0
50,0
25,25
c

Thank you for being so stubborn

Of course, you are right, I created https://github.com/LibreCAD/LibreCAD/issues/1101

LordOfBikes wrote

Thank you for being so stubborn
...

I like to think of it as "persistent..."  

Has 'stubborn' a negative touch?
If so, this was not my intention
The translators 1st choice was 'stubborn', the 2nd 'persistent'.
Seems that 1st choice is no warrant for best choice.

I suppose "stubborn" can have a negative connotation when it equates to being obstinate or "pig-headed".  In the context here I read between the lines and really took no offense.  The wonders of the english language....