Repository: pandas-dev/pandas

Issue:
BUG: `Series` slicing can fail for extension array `Index`
### Pandas version checks

- [X] I have checked that this issue has not already been reported.

- [X] I have confirmed this bug exists on the [latest version](https://pandas.pydata.org/docs/whatsnew/index.html) of pandas.

- [ ] I have confirmed this bug exists on the main branch of pandas.


### Reproducible Example

```python
import pandas as pd

s = pd.Series(range(5), index=pd.Index(range(5), dtype=int))
print(s.loc[4:5])  # works

# Fails with both `numpy`- and `pyarrow`-backed extension arrays for the index
s = pd.Series(range(5), index=pd.Index(range(5), dtype="Int64"))
print(s.loc[4:5])  # fails

s = pd.Series(range(5), index=pd.Index(range(5), dtype="int64[pyarrow]"))
print(s.loc[4:5])  # fails
```


### Issue Description

I ran into an issue where slicing a series (via `.loc`) works for when using an index with `dtype=int`, but fails when I cast the index to use either `numpy`- or `pyarrow`-backed extension arrays. 

### Expected Behavior

I think these are all valid `.loc` calls that should return the corresponding selection

### Installed Versions

<details>

```
INSTALLED VERSIONS
------------------
commit           : 8dab54d6573f7186ff0c3b6364d5e4dd635ff3e7
python           : 3.9.15.final.0
python-bits      : 64
OS               : Darwin
OS-release       : 21.6.0
Version          : Darwin Kernel Version 21.6.0: Thu Sep 29 20:12:57 PDT 2022; root:xnu-8020.240.7~1/RELEASE_X86_64
machine          : x86_64
processor        : i386
byteorder        : little
LC_ALL           : None
LANG             : en_US.UTF-8
LOCALE           : en_US.UTF-8

pandas           : 1.5.2
numpy            : 1.23.5
pytz             : 2022.6
dateutil         : 2.8.2
setuptools       : 59.8.0
pip              : 22.3.1
Cython           : None
pytest           : 7.2.0
hypothesis       : None
sphinx           : 4.5.0
blosc            : None
feather          : None
xlsxwriter       : None
lxml.etree       : None
html5lib         : 1.1
pymysql          : None
psycopg2         : None
jinja2           : 3.1.2
IPython          : 8.7.0
pandas_datareader: None
bs4              : 4.11.1
bottleneck       : None
brotli           :
fastparquet      : 2022.11.0
fsspec           : 2022.11.0
gcsfs            : None
matplotlib       : None
numba            : None
numexpr          : 2.8.3
odfpy            : None
openpyxl         : None
pandas_gbq       : None
pyarrow          : 10.0.1
pyreadstat       : None
pyxlsb           : None
s3fs             : 2022.11.0
scipy            : 1.9.3
snappy           :
sqlalchemy       : 1.4.44
tables           : 3.7.0
tabulate         : None
xarray           : 2022.11.0
xlrd             : None
xlwt             : None
zstandard        : None
tzdata           : None
```
</details>



Discussion:
I should also note that it seems important that the reproducer in slicing at the end of the series. Things work if one slices in the beginning or middle of the series

```python
In [6]: s = pd.Series(range(5), index=pd.Index(range(5), dtype="int64[pyarrow]"))

In [7]: s[2:3]
Out[7]:
2    2
dtype: int64

In [8]: s[:3]
Out[8]:
0    0
1    1
2    2
dtype: int64
```

Patch:
diff --git a/doc/source/whatsnew/v2.0.0.rst b/doc/source/whatsnew/v2.0.0.rst
index cbad169fe4d56..d3710b69dd4c1 100644
--- a/doc/source/whatsnew/v2.0.0.rst
+++ b/doc/source/whatsnew/v2.0.0.rst
@@ -833,6 +833,7 @@ Indexing
 ^^^^^^^^
 - Bug in :meth:`DataFrame.reindex` filling with wrong values when indexing columns and index for ``uint`` dtypes (:issue:`48184`)
 - Bug in :meth:`DataFrame.loc` coercing dtypes when setting values with a list indexer (:issue:`49159`)
+- Bug in :meth:`Series.loc` raising error for out of bounds end of slice indexer (:issue:`50161`)
 - Bug in :meth:`DataFrame.loc` raising ``ValueError`` with ``bool`` indexer and :class:`MultiIndex` (:issue:`47687`)
 - Bug in :meth:`DataFrame.__setitem__` raising ``ValueError`` when right hand side is :class:`DataFrame` with :class:`MultiIndex` columns (:issue:`49121`)
 - Bug in :meth:`DataFrame.reindex` casting dtype to ``object`` when :class:`DataFrame` has single extension array column when re-indexing ``columns`` and ``index`` (:issue:`48190`)
diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 53491d12e7172..3a875851510ba 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -6198,6 +6198,11 @@ def _maybe_cast_slice_bound(self, label, side: str_t):
         # We are a plain index here (sub-class override this method if they
         # wish to have special treatment for floats/ints, e.g. Float64Index and
         # datetimelike Indexes
+        # Special case numeric EA Indexes, since they are not handled by NumericIndex
+
+        if is_extension_array_dtype(self.dtype) and is_numeric_dtype(self.dtype):
+            return self._maybe_cast_indexer(label)
+
         # reject them, if index does not contain label
         if (is_float(label) or is_integer(label)) and label not in self:
             self._raise_invalid_indexer("slice", label)


Test patch:
diff --git a/pandas/tests/series/indexing/test_indexing.py b/pandas/tests/series/indexing/test_indexing.py
index 4efc14be3eb7e..387272eb807e8 100644
--- a/pandas/tests/series/indexing/test_indexing.py
+++ b/pandas/tests/series/indexing/test_indexing.py
@@ -10,6 +10,7 @@
 from pandas import (
     NA,
     DataFrame,
+    Index,
     IndexSlice,
     MultiIndex,
     Series,
@@ -366,6 +367,14 @@ def test_loc_setitem_nested_data_enlargement():
     tm.assert_series_equal(ser, expected)
 
 
+def test_loc_ea_numeric_index_oob_slice_end():
+    # GH#50161
+    ser = Series(1, index=Index([0, 1, 2], dtype="Int64"))
+    result = ser.loc[2:3]
+    expected = Series(1, index=Index([2], dtype="Int64"))
+    tm.assert_series_equal(result, expected)
+
+
 def test_getitem_bool_int_key():
     # GH#48653
     ser = Series({True: 1, False: 0})