Bug #920575: Add a workaround for GNU libc nl_langinfo()'s returning NULL.

(Reported by Matthias Klose)

2 files changed, 9 insertions, 2 deletions

diff --git a/Misc/NEWS b/Misc/NEWS
index c0e2afe..dfb6432 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -193,6 +193,9 @@ Core and builtins
 Extension modules
 -----------------
 
+- Bug #920575: A problem that _locale module segfaults on
+  nl_langinfo(ERA) caused by GNU libc's illegal NULL return is fixed.
+
 - array objects now support the copy module.  Also, their resizing
   scheme has been updated the same as for list objects.  The improves
   the performance (speed and memory usage) of append() operations.
diff --git a/Modules/_localemodule.c b/Modules/_localemodule.c
index 2cfda88..5edb7f3 100644
--- a/Modules/_localemodule.c
+++ b/Modules/_localemodule.c
@@ -592,8 +592,12 @@ PyLocale_nl_langinfo(PyObject* self, PyObject* args)
     }
 #endif
     for (i = 0; langinfo_constants[i].name; i++)
-	    if (langinfo_constants[i].value == item)
-		    return PyString_FromString(nl_langinfo(item));
+        if (langinfo_constants[i].value == item) {
+            /* Check NULL as a workaround for GNU libc's returning NULL
+               instead of an empty string for nl_langinfo(ERA).  */
+            const char *result = nl_langinfo(item);
+            return PyString_FromString(result != NULL ? result : "");
+        }
     PyErr_SetString(PyExc_ValueError, "unsupported langinfo constant");
     return NULL;
 }