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Author: rhshadrach

pandas/core/arrays/sparse/array.py

@@ -1570,8 +1570,8 @@ def cumsum(self, axis: AxisInt = 0, *args, **kwargs) -> SparseArray:
         if axis is not None and axis >= self.ndim:  # Mimic ndarray behaviour.
             raise ValueError(f"axis(={axis}) out of bounds")
 
-        if not self._null_fill_value and self.fill_value != 0:
-            return SparseArray(self.to_dense()).cumsum()
+        if not self._null_fill_value:
+            return SparseArray(self.to_dense(), fill_value=np.nan).cumsum()
 
         return SparseArray(
             self.sp_values.cumsum(),

pandas/tests/arrays/sparse/test_array.py

@@ -367,16 +367,24 @@ def test_cumsum_integer_no_recursion():
     # GH 62669: RecursionError in integer SparseArray.cumsum
     arr = SparseArray([1, 2, 3])
     result = arr.cumsum()
-    expected = SparseArray([1, 3, 6])
+    expected = SparseArray([1, 3, 6], fill_value=np.nan)
     tm.assert_sp_array_equal(result, expected)
 
     # Also test with some zeros interleaved
     arr2 = SparseArray([0, 1, 0, 2])
     result2 = arr2.cumsum()
-    expected2 = SparseArray([0, 1, 1, 3])
+    expected2 = SparseArray([0, 1, 1, 3], fill_value=np.nan)
     tm.assert_sp_array_equal(result2, expected2)
 
 
+def test_cumsum_float_fill_value_zero():
+    # GH 62669
+    arr = pd.arrays.SparseArray([1.0, 0.0, np.nan, 3.0], fill_value=0.0)
+    result = arr.cumsum()
+    expected = SparseArray([1.0, 1.0, None, 4.0], fill_value=np.nan)
+    tm.assert_sp_array_equal(result, expected)
+
+
 def test_setting_fill_value_updates():
     arr = SparseArray([0.0, np.nan], fill_value=0)
     arr.fill_value = np.nan