Polygon not rendering 'cleanly' - fill sometimes appears outside expected boundaries

[Tom1827]

What did you do?

rendered polygons

What did you expect to happen?

accurate rednering of polygons

What actually happened?

'dirty' polygon rendering, with drawing outside of expected boundaries

this is the polygon rendered by Pillow; you can clearly see the fill color (blue) outside of the expected boundary lines (white):

this is a polygon, using precisely the same data, rendered by pysdl2:

What versions of Pillow and Python are you using?

Pillow 9.1.1
Python 3.10.2 (on Windows)

Code to reproduce:

from PIL import Image, ImageDraw

i = Image.new("RGB", (1050, 1068))
draw = ImageDraw.Draw(i)

test_polygon = [(30.0, 629.4507134752477), (50.0, 629.8565139892041), (70.0, 627.2543706746618), 
                (90.0, 626.0154710958213), (110.0, 626.011874242351), (130.0, 625.3440687206069), 
                (150.0, 625.664018531622), (170.0, 625.4978763181073), (190.0, 626.8082520616501),
                (210.0, 628.4793899572998), (230.0, 625.5727005531411), (250.0, 626.6852232204809), 
                (270.0, 629.2271456013137), (290.0, 629.674604313272), (310.0, 629.6868878544574), 
                (330.0, 629.6868878544574), (350.0, 629.5207747265167), (370.0, 626.9244799578914), 
                (390.0, 625.4966243597871), (410.0, 627.1466394082299), (430.0, 626.8563010422029), 
                (450.0, 625.9732816358337), (470.0, 626.0223664538509), (490.0, 625.9939078255982), 
                (510.0, 626.3296698337327), (530.0, 628.102891777509), (550.0, 627.7136916475783), 
                (570.0, 627.7000106564611), (590.0, 628.2368838860209), (610.0, 628.9263631533747),
                (630.0, 629.4478207168099), (650.0, 629.529289231639), (670.0, 629.5638852462581), 
                (690.0, 629.6030138047543), (710.0, 626.5579731233461), (730.0, 625.0519611728187), 
                (750.0, 625.0578344827394), (770.0, 625.3224042542365), (790.0, 626.3760735193364),
                (810.0, 628.1560246482019), (830.0, 628.6247994798618), (850.0, 628.2015120730098), 
                (870.0, 627.6041293694293), (890.0, 626.6221235932012), (910.0, 625.696843383893),
                (930.0, 626.1766968392732), (950.0, 626.2595546558532), (970.0, 625.7111921762546),
                (990.0, 625.4764505087265), (1010.0, 626.4968501568546), (1030.0, 629.9504926228511),
                (1030.0, 630.0495073771489), (1010.0, 633.5031498431454), (990.0, 634.5235494912735),
                (970.0, 634.2888078237454), (950.0, 633.7404453441468), (930.0, 633.8233031607268),
                (910.0, 634.303156616107), (890.0, 633.3778764067988), (870.0, 632.3958706305707),
                (850.0, 631.7984879269902), (830.0, 631.3752005201382), (810.0, 631.8439753517981),
                (790.0, 633.6239264806636), (770.0, 634.6775957457635), (750.0, 634.9421655172606),
                (730.0, 634.9480388271813), (710.0, 633.4420268766539), (690.0, 630.3969861952457),
                (670.0, 630.4361147537419), (650.0, 630.470710768361), (630.0, 630.5521792831901),
                (610.0, 631.0736368466253), (590.0, 631.7631161139791), (570.0, 632.2999893435389),
                (550.0, 632.2863083524217), (530.0, 631.897108222491), (510.0, 633.6703301662673),
                (490.0, 634.0060921744018), (470.0, 633.9776335461491), (450.0, 634.0267183641663),
                (430.0, 633.1436989577971), (410.0, 632.8533605917701), (390.0, 634.5033756402129),
                (370.0, 633.0755200421086), (350.0, 630.4792252734833), (330.0, 630.3131121455426),
                (310.0, 630.3131121455426), (290.0, 630.325395686728), (270.0, 630.7728543986863),
                (250.0, 633.3147767795191), (230.0, 634.4272994468589), (210.0, 631.5206100427002),
                (190.0, 633.1917479383499), (170.0, 634.5021236818927), (150.0, 634.335981468378),
                (130.0, 634.6559312793931), (110.0, 633.988125757649), (90.0, 633.9845289041787),
                (70.0, 632.7456293253382), (50.0, 630.1434860107959), (30.0, 630.5492865247523)]

draw.polygon(test_polygon, fill=(0, 0, 255, 255), outline=(255, 255, 255, 0))

i.save('test.png')

[radarhere]

Testing, I find this was fixed by #6303. If you upgrade to Pillow 9.2.0, this should no longer be an issue.

[radarhere]

@Tom1827 unless you have any further comments. this is resolved.

[Tom1827]

Thank you, and my apologies.