Convert booleans to integers in IntVar.set. Fixes #671741.

Return booleans from _tkinter.getboolean.
Convert booleans to Tcl booleans in AsObj.

Lib/lib-tk/Tkinter.py

@@ -234,6 +234,12 @@ class IntVar(Variable):
         MASTER can be given as master widget."""
         Variable.__init__(self, master)
 
+    def set(self, value):
+        """Set the variable to value, converting booleans to integers."""
+        if isinstance(value, bool):
+            value = int(value)
+        return Variable.set(self, value)
+
     def get(self):
         """Return the value of the variable as an integer."""
         return getint(self._tk.globalgetvar(self._name))

Modules/_tkinter.c

@@ -868,6 +868,8 @@ AsObj(PyObject *value)
 	if (PyString_Check(value))
 		return Tcl_NewStringObj(PyString_AS_STRING(value),
 					PyString_GET_SIZE(value));
+	else if (PyBool_Check(value))
+		return Tcl_NewBooleanObj(PyObject_IsTrue(value));
 	else if (PyInt_Check(value))
 		return Tcl_NewLongObj(PyInt_AS_LONG(value));
 	else if (PyFloat_Check(value))
@@ -1739,7 +1741,7 @@ Tkapp_GetBoolean(PyObject *self, PyObject *args)
 		return NULL;
 	if (Tcl_GetBoolean(Tkapp_Interp(self), s, &v) == TCL_ERROR)
 		return Tkinter_Error(self);
-	return Py_BuildValue("i", v);
+	return PyBool_FromLong(v);
 }
 
 static PyObject *