Path join type not correct in first node

[elecman]

Using:

Inkscape 0.92.2 2405546, 2018-03-11
Archlinux updated

Steps to reproduce:

1. Draw a closed poligon with sharp nodes using Bézier tool. It should be very small compared with an A4 sheet.
2. Open fill and stroke.
3. Set round join in stroke style.

Actual program behaviour:

Every join gets rounded except the first node, the one where the beginning and the end of the path merge.

Expected program behaviour:

Every join should get rounded.

Workaround:

Put the first/final/closing node in a place where you need a smooth node, if you need any, and the rest in the corners.

Extra:

There is a sample file posted in comments. If you open it in Firefox, for example, you can see that it manages this well, showing expected behaviour.

[José Alberto (josealberto4444)]

Also affects me. I've rewritten the whole bug report to improve it.

[Pierre-Yves Mutrux (muxson)]

Same bug found with Inkscape 0.92.4 (latest as of today), running Windows 10 Pro.

Trying to narrow down when it occurs, I see that the error occurs at the start/end join (as described in the initial bug report), when specific stroke widths are selected.
It also depends on the angle between the two segments.
Also, the node has to be a corner and the join type has to be Round (sounds obvious but maybe not...).
For a 90° angle, the join becomes a miter join when the stroke width is between 0.118 mm and 0.682 mm or 0.005 in and 0.026 in.
For a 120° angle (in an hexagone for example), the join becomes a miter join when the stroke width is between 0.108 mm and 1.492 mm or 0.005 in - 0.058 in.

Hope this helps,
Muxson

[Pierre-Yves Mutrux (muxson)]

Just discovered that the values I published a few hours ago are dependent to the Custom size and Scale (Document Properties). Not sure why and how but here is what I used, so that you can reproduce the bug:
Width 36 in, Height 24 in, and Scale x and Y: 1.00

[Nathan Lee (nathan.lee)]

Closing as part of migration of bugs to GitLab. Issue was opened here: https://gitlab.com/inkscape/inkscape/-/issues/359

Please report any new issues in https://inkscape.org/report