[pygobject] pygspawn: improve error checking

[Ryan Lortie <ryanl src gnome org>]

commit 945fd18e531c2131440af93dcd89f6c63abbfd7c
Author: Ryan Lortie <desrt desrt ca>
Date:   Tue Feb 7 13:42:19 2012 -0500

    pygspawn: improve error checking
    
    gspawn 'argv' and 'envp' parameters expect sequences of strings.  This
    is enforced by checking that the passed argument is a sequence and that
    each item returned from it is a string.
    
    We do now, however, verify that each item can be successfully taken from
    the sequence.  'os.environ' is an example of an object that passes
    PySequence_Check() but fails to return objects from PySequence_ITEM().
    
    Add a simple NULL check to avoid the crash.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=669594

 gi/_glib/pygspawn.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gi/_glib/pygspawn.c b/gi/_glib/pygspawn.c
index 309b83d..cfa5555 100644
--- a/gi/_glib/pygspawn.c
+++ b/gi/_glib/pygspawn.c
@@ -150,7 +150,7 @@ pyglib_spawn_async(PyObject *object, PyObject *args, PyObject *kwargs)
     argv = g_new0(char *, len + 1);
     for (i = 0; i < len; ++i) {
         PyObject *tmp = PySequence_ITEM(pyargv, i);
-        if (!PYGLIB_PyUnicode_Check(tmp)) {
+        if (tmp == NULL || !PYGLIB_PyUnicode_Check(tmp)) {
             PyErr_SetString(PyExc_TypeError,
                             "gi._glib.spawn_async: "
 			    "first argument must be a sequence of strings");
@@ -175,7 +175,7 @@ pyglib_spawn_async(PyObject *object, PyObject *args, PyObject *kwargs)
         envp = g_new0(char *, len + 1);
         for (i = 0; i < len; ++i) {
             PyObject *tmp = PySequence_ITEM(pyenvp, i);
-            if (!PYGLIB_PyUnicode_Check(tmp)) {
+            if (tmp == NULL || !PYGLIB_PyUnicode_Check(tmp)) {
                 PyErr_SetString(PyExc_TypeError,
                                 "gi._glib.spawn_async: "
 				"second argument must be a sequence of strings");