Fix T44567: inset polygon added crash

Crash caused by some vertices in the input model being doubled.
The code to test for the maximum inset deduped the vertices
but the faces were not remapped. Fixed by having that test code
not dedup the vertices.

mesh_inset/geom.py

@@ -67,11 +67,12 @@ def Quantize(p):
 
         return tuple([int(round(v * INVDISTTOL)) for v in p])
 
-    def AddPoint(self, p):
+    def AddPoint(self, p, allowdups = False):
         """Add point p to the Points set and return vertex number.
 
         If there is an existing point which quantizes the same,,
         don't add a new one but instead return existing index.
+        Except if allowdups is True, don't do that deduping.
 
         Args:
           p: tuple of float - coordinates (2-tuple or 3-tuple)
@@ -80,14 +81,14 @@ def AddPoint(self, p):
         """
 
         qp = Points.Quantize(p)
-        if qp in self.invmap:
+        if qp in self.invmap and not allowdups:
             return self.invmap[qp]
         else:
             self.invmap[qp] = len(self.pos)
             self.pos.append(p)
             return len(self.pos) - 1
 
-    def AddPoints(self, points):
+    def AddPoints(self, points, allowdups = False):
         """Add another set of points to this set.
 
         We need to return a mapping from indices
@@ -102,7 +103,7 @@ def AddPoints(self, points):
 
         vmap = [0] * len(points.pos)
         for i in range(len(points.pos)):
-            vmap[i] = self.AddPoint(points.pos[i])
+            vmap[i] = self.AddPoint(points.pos[i], allowdups)
         return vmap
 
     def AddZCoord(self, z):

mesh_inset/offset.py

@@ -706,7 +706,7 @@ def MaxAmount(self):
         # so don't add points that won't be used when
         # really do a Build with a smaller amount
         test_points = geom.Points()
-        test_points.AddPoints(self.polyarea.points)
+        test_points.AddPoints(self.polyarea.points, True)
         save_points = self.polyarea.points
         self.polyarea.points = test_points
         self.Build()