Infill bug in vase mode

[btthrt]

What happened?

No infill in these areas

Project file & How to reproduce

Slice this file in vase mode with 6 bottom layers and whatever infill pattern you want.
Get almost no infill in tight areas, only bottom and top layer hanging.
VaseV649.zip

Version

2.3.57.12

Operating system

windows 11

Printer model

voron 2.4

[btthrt]

Ok, small clarification, set external perimeter to something close to 0.6-0.7mm for .4 nozzle
Then try slicing

[supermerill]

And why not giving me your project (as requested in the issue template) instead of the stl, so I can have your settings?

[btthrt]

@supermerill sorry, I'm a little bit retarded

Here, please verify my stupidity. :)

VaseV649 bugged.zip

[supermerill]

That comes from a code that prevent too much solid infill when sparse infill is set at 0. Will deactivate it for spiral vase.
comment from code, for reference:

                            // if we're printing a hollow object we discard any solid shell thinner
                            // than a perimeter width, since it's probably just crossing a sloping wall
                            // and it's not wanted in a hollow print even if it would make sense when
                            // obeying the solid shell count option strictly (DWIM!)