Treat zero length line as line to avoid unintuitive behavior

labelme/utils/qt.py

@@ -91,7 +91,7 @@ def distancetoline(point, line):
     if np.dot((p3 - p2), (p1 - p2)) < 0:
         return np.linalg.norm(p3 - p2)
     if np.linalg.norm(p2 - p1) == 0:
-        return 0
+        return np.linalg.norm(p3 - p1)
     return np.linalg.norm(np.cross(p2 - p1, p1 - p3)) / np.linalg.norm(p2 - p1)