Fix compiling error when missing gdbm version macros

Author: zhangyangyu

Lib/test/pythoninfo.py

@@ -527,11 +527,11 @@ def collect_cc(info_add):
 
 def collect_gdbm(info_add):
     try:
-        import _gdbm
+        from _gdbm import _GDBM_VERSION
     except ImportError:
         return
 
-    info_add('gdbm.GDBM_VERSION', '.'.join(map(str, _gdbm._GDBM_VERSION)))
+    info_add('gdbm.GDBM_VERSION', '.'.join(map(str, _GDBM_VERSION)))
 
 
 def collect_info(info):

Modules/_gdbmmodule.c

@@ -678,6 +678,7 @@ PyInit__gdbm(void) {
         goto error;
     }
 
+#if defined(GDBM_VERSION_MAJOR) && defined(GDBM_VERSION_MINOR) && defined(GDBM_VERSION_PATCH)
     PyObject *obj = Py_BuildValue("iii", GDBM_VERSION_MAJOR,
                                   GDBM_VERSION_MINOR, GDBM_VERSION_PATCH);
     if (obj == NULL) {
@@ -687,6 +688,7 @@ PyInit__gdbm(void) {
         Py_DECREF(obj);
         goto error;
     }
+#endif
 
     return m;