Index: Modules/posixmodule.c
===================================================================
--- Modules/posixmodule.c	(révision 80008)
+++ Modules/posixmodule.c	(copie de travail)
@@ -2689,15 +2689,18 @@
 	if (!PyArg_ParseTuple(args, "u:system", &command))
 		return NULL;
 #else
+	PyObject *command_obj;
 	char *command;
-	if (!PyArg_ParseTuple(args, "s:system", &command))
+	if (!PyArg_ParseTuple(args, "O&:system", PyUnicode_FSConverter, &command_obj))
 		return NULL;
 #endif
 	Py_BEGIN_ALLOW_THREADS
 #ifdef MS_WINDOWS
 	sts = _wsystem(command);
 #else
+	command = bytes2str(command_obj, 1);
 	sts = system(command);
+	release_bytes(command_obj);
 #endif
 	Py_END_ALLOW_THREADS
 	return PyLong_FromLong(sts);
@@ -3168,6 +3171,7 @@
 	for (pos = 0; pos < i; pos++) {
 		char *p, *k, *v;
 		size_t len;
+		PyObject *val2;
 
 		key = PyList_GetItem(keys, pos);
 		val = PyList_GetItem(vals, pos);
@@ -3177,27 +3181,30 @@
 		if (!PyArg_Parse(
 			    key,
 			    "s;execve() arg 3 contains a non-string key",
-			    &k) ||
-		    !PyArg_Parse(
-			    val,
-			    "s;execve() arg 3 contains a non-string value",
-			    &v))
+			    &k))
 		{
 			goto fail_2;
 		}
 
+		val2 = PyUnicode_AsEncodedString(val,
+			Py_FileSystemDefaultEncoding, "surrogateescape");
+		if (val2 == NULL)
+			goto fail_2;
+
 #if defined(PYOS_OS2)
         /* Omit Pseudo-Env Vars that Would Confuse Programs if Passed On */
         if (stricmp(k, "BEGINLIBPATH") != 0 && stricmp(k, "ENDLIBPATH") != 0) {
 #endif
-		len = PyUnicode_GetSize(key) + PyUnicode_GetSize(val) + 2;
+		len = PyUnicode_GetSize(key) + PyBytes_GET_SIZE(val2) + 2;
 		p = PyMem_NEW(char, len);
 		if (p == NULL) {
 			PyErr_NoMemory();
+			Py_DECREF(val2);
 			goto fail_2;
 		}
-		PyOS_snprintf(p, len, "%s=%s", k, v);
+		PyOS_snprintf(p, len, "%s=%s", k, PyBytes_AsString(val2));
 		envlist[envc++] = p;
+		Py_DECREF(val2);
 #if defined(PYOS_OS2)
     }
 #endif