add missing NULL checks to get_coding_spec (closes #24854)
diff --git a/Parser/tokenizer.c b/Parser/tokenizer.c
index d0e4a0e..109c0ee 100644
--- a/Parser/tokenizer.c
+++ b/Parser/tokenizer.c
@@ -235,7 +235,10 @@
 
             if (begin < t) {
                 char* r = new_string(begin, t - begin);
-                char* q = get_normal_name(r);
+                char* q;
+                if (!r)
+                    return NULL;
+                q = get_normal_name(r);
                 if (r != q) {
                     PyMem_FREE(r);
                     r = new_string(q, strlen(q));