In pwd, spwd and grp modules, make the get*nam() functions encode
their arguments using the file system encoding and the
"surrogateescape" error handler.

Index: Modules/pwdmodule.c
===================================================================
--- Modules/pwdmodule.c.orig
+++ Modules/pwdmodule.c
@@ -130,14 +130,25 @@
 {
 	char *name;
 	struct passwd *p;
-	if (!PyArg_ParseTuple(args, "s:getpwnam", &name))
+	PyObject *arg, *bytes, *retval = NULL;
+
+	if (!PyArg_ParseTuple(args, "U:getpwnam", &arg))
+		return NULL;
+	if ((bytes = PyUnicode_AsEncodedString(arg,
+					       Py_FileSystemDefaultEncoding,
+					       "surrogateescape")) == NULL)
 		return NULL;
+	if (PyBytes_AsStringAndSize(bytes, &name, NULL) == -1)
+		goto out;
 	if ((p = getpwnam(name)) == NULL) {
 		PyErr_Format(PyExc_KeyError,
 			     "getpwnam(): name not found: %s", name);
-		return NULL;
+		goto out;
 	}
-	return mkpwent(p);
+	retval = mkpwent(p);
+out:
+	Py_DECREF(bytes);
+	return retval;
 }
 
 #ifdef HAVE_GETPWENT
Index: Modules/spwdmodule.c
===================================================================
--- Modules/spwdmodule.c.orig
+++ Modules/spwdmodule.c
@@ -116,13 +116,24 @@
 {
 	char *name;
 	struct spwd *p;
-	if (!PyArg_ParseTuple(args, "s:getspnam", &name))
+	PyObject *arg, *bytes, *retval = NULL;
+
+	if (!PyArg_ParseTuple(args, "U:getspnam", &arg))
+		return NULL;
+	if ((bytes = PyUnicode_AsEncodedString(arg,
+					       Py_FileSystemDefaultEncoding,
+					       "surrogateescape")) == NULL)
 		return NULL;
+	if (PyBytes_AsStringAndSize(bytes, &name, NULL) == -1)
+		goto out;
 	if ((p = getspnam(name)) == NULL) {
 		PyErr_SetString(PyExc_KeyError, "getspnam(): name not found");
-		return NULL;
+		goto out;
 	}
-	return mkspent(p);
+	retval = mkspent(p);
+out:
+	Py_DECREF(bytes);
+	return retval;
 }
 
 #endif /* HAVE_GETSPNAM */
Index: Modules/grpmodule.c
===================================================================
--- Modules/grpmodule.c.orig
+++ Modules/grpmodule.c
@@ -107,25 +107,28 @@
 }
 
 static PyObject *
-grp_getgrnam(PyObject *self, PyObject *pyo_name)
+grp_getgrnam(PyObject *self, PyObject *args)
 {
-    PyObject *py_str_name;
     char *name;
     struct group *p;
+    PyObject *arg, *bytes, *retval = NULL;
 
-    py_str_name = PyObject_Str(pyo_name);
-    if (!py_str_name)
-	    return NULL;
-    name = _PyUnicode_AsString(py_str_name);
+    if (!PyArg_ParseTuple(args, "U:getgrnam", &arg))
+        return NULL;
+    if ((bytes = PyUnicode_AsEncodedString(arg, Py_FileSystemDefaultEncoding,
+                                           "surrogateescape")) == NULL)
+        return NULL;
+    if (PyBytes_AsStringAndSize(bytes, &name, NULL) == -1)
+        goto out;
     
     if ((p = getgrnam(name)) == NULL) {
 	PyErr_Format(PyExc_KeyError, "getgrnam(): name not found: %s", name);
-	Py_DECREF(py_str_name);
-        return NULL;
+        goto out;
     }
-
-    Py_DECREF(py_str_name);
-    return mkgrent(p);
+    retval = mkgrent(p);
+out:
+    Py_DECREF(bytes);
+    return retval;
 }
 
 static PyObject *
@@ -155,7 +158,7 @@
      "getgrgid(id) -> tuple\n\
 Return the group database entry for the given numeric group ID.  If\n\
 id is not valid, raise KeyError."},
-    {"getgrnam",	grp_getgrnam,	METH_O,
+    {"getgrnam",	grp_getgrnam,	METH_VARARGS,
      "getgrnam(name) -> tuple\n\
 Return the group database entry for the given group name.  If\n\
 name is not valid, raise KeyError."},