fixed column name issue for column wise concat

Author: Anurag-Varma

pandas/core/reshape/concat.py

@@ -482,13 +482,13 @@ def _sanitize_mixed_ndim(
                 if axis == 1:
                     # doing a row-wise concatenation so need everything
                     # to line up
-                    if name is None:
-                        name_none_flag = True
-                        name = 0
+                    name = 0
                 else:
                     # doing a column-wise concatenation so need series
                     # to have unique names
-                    name = current_column
+                    if name is None:
+                        name_none_flag = True
+                        name = current_column
                     current_column += 1
                 obj = sample._constructor(obj, copy=False)
                 if isinstance(obj, ABCDataFrame) and name_none_flag:

pandas/tests/reshape/concat/test_concat.py

@@ -280,7 +280,7 @@ def test_concat_mixed_objs_columns(self):
         tm.assert_frame_equal(result, expected)
 
         expected = DataFrame(
-            np.repeat(arr, 5).reshape(-1, 5), index=index, columns=[0, 0, 0, 0, 0]
+            np.repeat(arr, 5).reshape(-1, 5), index=index, columns=[0, 0, 1, 2, 3]
         )
         result = concat([s1, df, s2, s2, s1], axis=1)
         tm.assert_frame_equal(result, expected)