Issue #13645: pyc files now contain the size of the corresponding source
code, to avoid timestamp collisions (especially on filesystems with a low
timestamp resolution) when checking for freshness of the bytecode.
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index c8d1e90..761110a 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -1844,6 +1844,8 @@
                    "Bad magic number in .pyc file");
         return NULL;
     }
+    /* Skip mtime and size */
+    (void) PyMarshal_ReadLongFromFile(fp);
     (void) PyMarshal_ReadLongFromFile(fp);
     v = PyMarshal_ReadLastObjectFromFile(fp);
     fclose(fp);