Fixed int.real, int.numerator etc. returns wrong value when it's int type. (RustPython#3715)

Author: killme2008

extra_tests/snippets/builtin_int.py

@@ -324,3 +324,25 @@ def __int__(self):
 assert 1 is 1  # noqa
 x = 6
 assert 5 is (x-1)  # noqa
+
+
+# test issue3687
+import math
+big_int = 1000000
+small_int = 3
+assert big_int.real is big_int
+assert big_int.numerator is big_int
+assert math.trunc(big_int) is big_int
+assert math.floor(big_int) is big_int
+assert math.ceil(big_int) is big_int
+assert small_int.real is small_int
+assert small_int.numerator is small_int
+assert math.trunc(small_int) is small_int
+assert math.floor(small_int) is small_int
+assert math.ceil(small_int) is small_int
+
+# test subclassing int
+class SubInt(int): pass
+subint = int.__new__(SubInt, 11)
+assert subint.real is not subint
+assert type(subint.real) is int

vm/src/builtins/int.rs

@@ -561,18 +561,18 @@ impl PyInt {
     }
 
     #[pymethod(magic)]
-    fn trunc(zelf: PyRef<Self>) -> PyRef<Self> {
-        zelf
+    fn trunc(zelf: PyRef<Self>, vm: &VirtualMachine) -> PyRef<Self> {
+        Self::clone_if_subclass(zelf, vm)
     }
 
     #[pymethod(magic)]
-    fn floor(zelf: PyRef<Self>) -> PyRef<Self> {
-        zelf
+    fn floor(zelf: PyRef<Self>, vm: &VirtualMachine) -> PyRef<Self> {
+        Self::clone_if_subclass(zelf, vm)
     }
 
     #[pymethod(magic)]
-    fn ceil(zelf: PyRef<Self>) -> PyRef<Self> {
-        zelf
+    fn ceil(zelf: PyRef<Self>, vm: &VirtualMachine) -> PyRef<Self> {
+        Self::clone_if_subclass(zelf, vm)
     }
 
     #[pymethod(magic)]
@@ -618,8 +618,8 @@ impl PyInt {
     }
 
     #[pymethod]
-    fn conjugate(zelf: PyRef<Self>) -> PyRef<Self> {
-        zelf
+    fn conjugate(zelf: PyRef<Self>, vm: &VirtualMachine) -> PyRef<Self> {
+        Self::clone_if_subclass(zelf, vm)
     }
 
     #[pyclassmethod]
@@ -688,10 +688,18 @@ impl PyInt {
         Ok(bytes.into())
     }
 
+    #[inline]
+    fn clone_if_subclass(zelf: PyRef<Self>, vm: &VirtualMachine) -> PyRef<Self> {
+        if zelf.class().is(&vm.ctx.types.int_type) {
+            return zelf;
+        }
+
+        vm.ctx.new_bigint(&zelf.value)
+    }
+
     #[pyproperty]
-    fn real(&self, vm: &VirtualMachine) -> PyRef<Self> {
-        // subclasses must return int here
-        vm.ctx.new_bigint(&self.value)
+    fn real(zelf: PyRef<Self>, vm: &VirtualMachine) -> PyRef<Self> {
+        Self::clone_if_subclass(zelf, vm)
     }
 
     #[pyproperty]
@@ -700,8 +708,8 @@ impl PyInt {
     }
 
     #[pyproperty]
-    fn numerator(zelf: PyRef<Self>) -> PyRef<Self> {
-        zelf
+    fn numerator(zelf: PyRef<Self>, vm: &VirtualMachine) -> PyRef<Self> {
+        Self::clone_if_subclass(zelf, vm)
     }
 
     #[pyproperty]