Merge pull request matplotlib#23430 from scottshambaugh/3d_div0_warning

Fix divide by 0 runtime warning

Author: timhoffm

lib/mpl_toolkits/mplot3d/proj3d.py

@@ -21,7 +21,7 @@ def _line2d_seg_dist(p1, p2, p0):
 
     x01 = np.asarray(p0[0]) - p1[0]
     y01 = np.asarray(p0[1]) - p1[1]
-    if np.all(p1 == p2):
+    if np.all(p1[0:2] == p2[0:2]):
         return np.hypot(x01, y01)
 
     x21 = p2[0] - p1[0]

lib/mpl_toolkits/tests/test_mplot3d.py

@@ -1011,11 +1011,13 @@ def test_lines_dists():
 def test_lines_dists_nowarning():
     # Smoke test to see that no RuntimeWarning is emitted when two first
     # arguments are the same, see GH#22624
-    p0 = (10, 30)
-    p1 = (20, 150)
-    proj3d._line2d_seg_dist(p0, p0, p1)
+    p0 = (10, 30, 50)
+    p1 = (10, 30, 20)
+    p2 = (20, 150)
+    proj3d._line2d_seg_dist(p0, p0, p2)
+    proj3d._line2d_seg_dist(p0, p1, p2)
     p0 = np.array(p0)
-    proj3d._line2d_seg_dist(p0, p0, p1)
+    proj3d._line2d_seg_dist(p0, p0, p2)
 
 
 def test_autoscale():