Fixed connecting discontiguous corners

Tests/test_imagedraw.py

@@ -1674,6 +1674,9 @@ def test_continuous_horizontal_edges_polygon() -> None:
 def test_discontiguous_corners_polygon() -> None:
     img, draw = create_base_image_draw((84, 68))
     draw.polygon(((1, 21), (34, 4), (71, 1), (38, 18)), BLACK)
+    draw.polygon(
+        ((82, 29), (82, 26), (82, 24), (67, 22), (52, 29), (52, 15), (67, 22)), BLACK
+    )
     draw.polygon(((71, 44), (38, 27), (1, 24)), BLACK)
     draw.polygon(
         ((38, 66), (5, 49), (77, 49), (47, 66), (82, 63), (82, 47), (1, 47), (1, 63)),

src/libImaging/Draw.c

@@ -501,7 +501,8 @@ polygon_generic(
                     // Needed to draw consistent polygons
                     xx[j] = xx[j - 1];
                     j++;
-                } else if (current->dx != 0 && roundf(xx[j - 1]) == xx[j - 1]) {
+                } else if (current->dx != 0 && j % 2 == 1 &&
+                           roundf(xx[j - 1]) == xx[j - 1]) {
                     // Connect discontiguous corners
                     for (k = 0; k < i; k++) {
                         Edge *other_edge = edge_table[k];
@@ -510,10 +511,8 @@ polygon_generic(
                             continue;
                         }
                         // Check if the two edges join to make a corner
-                        if (((ymin == current->ymin && ymin == other_edge->ymin) ||
-                             (ymin == current->ymax && ymin == other_edge->ymax)) &&
-                            xx[j - 1] == (ymin - other_edge->y0) * other_edge->dx +
-                                             other_edge->x0) {
+                        if (xx[j - 1] ==
+                            (ymin - other_edge->y0) * other_edge->dx + other_edge->x0) {
                             // Determine points from the edges on the next row
                             // Or if this is the last row, check the previous row
                             int offset = ymin == ymax ? -1 : 1;