fix fmean/fsum ValueError and test_inv_cdf

Lib/test/test_statistics.py

@@ -1950,8 +1950,6 @@ class TestFMean(unittest.TestCase):
         with self.assertRaises(TypeError):
             fmean([10, 20, 60], 70)                 # too many arguments
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_special_values(self):
         # Rules for special values are inherited from math.fsum()
         fmean = statistics.fmean
@@ -2913,12 +2911,7 @@ class TestNormalDistPython(unittest.TestCase, TestNormalDist):
 
     def tearDown(self):
         sys.modules['statistics'] = statistics
-
-    # TODO: RUSTPYTHON, ValueError: math domain error
-    @unittest.expectedFailure
-    def test_inv_cdf(self): # TODO: RUSTPYTHON, remove when this passes
-        super().test_inv_cdf() # TODO: RUSTPYTHON, remove when this passes
-
+ 
 
 @unittest.skipUnless(c_statistics, 'requires _statistics')
 class TestNormalDistC(unittest.TestCase, TestNormalDist):

stdlib/src/math.rs

@@ -211,6 +211,9 @@ mod math {
     #[pyfunction]
     fn sqrt(value: ArgIntoFloat, vm: &VirtualMachine) -> PyResult<f64> {
         let value = *value;
+        if value.is_nan() {
+            return Ok(value);
+        }
         if value.is_sign_negative() {
             return Err(vm.new_value_error("math domain error".to_owned()));
         }
@@ -664,7 +667,7 @@ mod math {
         }
         if special_sum != 0.0 {
             return if inf_sum.is_nan() {
-                Err(vm.new_overflow_error("-inf + inf in fsum".to_owned()))
+                Err(vm.new_value_error("-inf + inf in fsum".to_owned()))
             } else {
                 Ok(special_sum)
             };