Move check up, add test for EA

Author: mroeschke

pandas/core/indexes/base.py

@@ -499,6 +499,13 @@ def __new__(
         if not copy and isinstance(data, (ABCSeries, Index)):
             refs = data._references
 
+        if isinstance(data, (ExtensionArray, np.ndarray)):
+            # GH 63306
+            if copy is not False:
+                if dtype is None or astype_is_view(data.dtype, dtype):
+                    data = data.copy()
+                    copy = False
+
         # range
         if isinstance(data, (range, RangeIndex)):
             result = RangeIndex(start=data, copy=bool(copy), name=name)
@@ -517,13 +524,7 @@ def __new__(
             pass
 
         elif isinstance(data, (np.ndarray, ABCMultiIndex)):
-            if isinstance(data, np.ndarray):
-                if copy is not False:
-                    if dtype is None or astype_is_view(data.dtype, pandas_dtype(dtype)):
-                        # GH 63306
-                        data = data.copy()
-                        copy = False
-            elif isinstance(data, ABCMultiIndex):
+            if isinstance(data, ABCMultiIndex):
                 data = data._values
 
             if data.dtype.kind not in "iufcbmM":

pandas/tests/copy_view/index/test_index.py

@@ -5,6 +5,7 @@
     DataFrame,
     Index,
     Series,
+    array,
 )
 import pandas._testing as tm
 from pandas.tests.copy_view.util import get_array
@@ -158,6 +159,12 @@ def test_constructor_copy_input_ndarray_default():
     assert not np.shares_memory(arr, get_array(idx))
 
 
+def test_constructor_copy_input_ea_default():
+    arr = array([0, 1], dtype="Int64")
+    idx = Index(arr)
+    assert not tm.shares_memory(arr, idx.array)
+
+
 def test_series_from_temporary_index_readonly_data():
     # GH 63370
     arr = np.array([0, 1], dtype=np.dtype(np.int8))