fix div 0 error of split (#49958)

paddle/phi/infermeta/unary.cc

@@ -3654,6 +3654,10 @@ void SplitWithNumInferMeta(const MetaTensor& x,
     auto input_axis_dim = x.dims().at(axis_value);
     // step1: get formated sections
     std::vector<int64_t> sections_vec;
+    PADDLE_ENFORCE_NE(
+        num,
+        0,
+        phi::errors::InvalidArgument("Attr(num_or_sections) should not be 0."));
     PADDLE_ENFORCE_EQ(input_axis_dim % num,
                       0,
                       phi::errors::InvalidArgument(

python/paddle/fluid/tests/unittests/test_split_op.py

@@ -358,6 +358,14 @@ class TestSplitOpError(unittest.TestCase):
 
             self.assertRaises(TypeError, test_axis_type_tensor)
 
+        with paddle.fluid.dygraph.guard():
+
+            def test_0_num_tensor():
+                x = paddle.uniform([1, 1, 1], dtype='float32')
+                paddle.split(x, num_or_sections=0)
+
+            self.assertRaises(ValueError, test_0_num_tensor)
+
 
 class API_TestSplit(unittest.TestCase):
     def test_out(self):