Issue #23998: PyImport_ReInitLock() now checks for lock allocation error

Misc/NEWS

@@ -213,6 +213,11 @@ Tools/Demos
   if Argument Clinic processes the same symbol multiple times, and it's emitted
   at the end of all processing rather than immediately after the first use.
 
+C API
+-----
+
+- Issue #23998: PyImport_ReInitLock() now checks for lock allocation error
+
 
 What's New in Python 3.5.0 alpha 3?
 ===================================

Python/import.c

@@ -209,8 +209,12 @@ _PyImport_ReleaseLock(void)
 void
 _PyImport_ReInitLock(void)
 {
-    if (import_lock != NULL)
+    if (import_lock != NULL) {
         import_lock = PyThread_allocate_lock();
+        if (import_lock == NULL) {
+            Py_FatalError("PyImport_ReInitLock failed to create a new lock");
+        }
+    }
     if (import_lock_level > 1) {
         /* Forked as a side effect of import */
         long me = PyThread_get_thread_ident();