From abaaf8818867c3d24ebe4a6a0dffb46849a74fd6 Mon Sep 17 00:00:00 2001
From: Patrick Hoefler <61934744+phofl@users.noreply.github.com>
Date: Wed, 15 Mar 2023 11:25:14 +0100
Subject: [PATCH] Backport PR #51974: BUG: astype_view check raising on minimum
 versions build

---
 pandas/core/dtypes/astype.py          |  5 ++++-
 pandas/tests/copy_view/test_astype.py | 10 ++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/pandas/core/dtypes/astype.py b/pandas/core/dtypes/astype.py
index 7ae5993c857e2..87a36aed418f9 100644
--- a/pandas/core/dtypes/astype.py
+++ b/pandas/core/dtypes/astype.py
@@ -263,6 +263,9 @@ def astype_is_view(dtype: DtypeObj, new_dtype: DtypeObj) -> bool:
     -------
     True if new data is a view or not guaranteed to be a copy, False otherwise
     """
+    if isinstance(dtype, np.dtype) and not isinstance(new_dtype, np.dtype):
+        new_dtype, dtype = dtype, new_dtype
+
     if dtype == new_dtype:
         return True
 
@@ -290,7 +293,7 @@ def astype_is_view(dtype: DtypeObj, new_dtype: DtypeObj) -> bool:
         numpy_dtype = dtype
 
     if new_numpy_dtype is None and isinstance(new_dtype, np.dtype):
-        numpy_dtype = new_dtype
+        new_numpy_dtype = new_dtype
 
     if numpy_dtype is not None and new_numpy_dtype is not None:
         # if both have NumPy dtype or one of them is a numpy dtype
diff --git a/pandas/tests/copy_view/test_astype.py b/pandas/tests/copy_view/test_astype.py
index 73343976e92fb..15351967c8d83 100644
--- a/pandas/tests/copy_view/test_astype.py
+++ b/pandas/tests/copy_view/test_astype.py
@@ -2,7 +2,9 @@
 import pytest
 
 from pandas.compat import pa_version_under7p0
+import pandas.util._test_decorators as td
 
+import pandas as pd
 from pandas import (
     DataFrame,
     Series,
@@ -84,6 +86,14 @@ def test_astype_different_target_dtype(using_copy_on_write, dtype):
     tm.assert_frame_equal(df2, df_orig.astype(dtype))
 
 
+@td.skip_array_manager_invalid_test
+def test_astype_numpy_to_ea():
+    ser = Series([1, 2, 3])
+    with pd.option_context("mode.copy_on_write", True):
+        result = ser.astype("Int64")
+    assert np.shares_memory(get_array(ser), get_array(result))
+
+
 @pytest.mark.parametrize(
     "dtype, new_dtype", [("object", "string"), ("string", "object")]
 )