Given the persistent id code a shot at a class before calling save_global().

Some persistent picklers (well, probably, the *only* persistent
pickler) would like to pickle some classes in a special way.

Lib/pickle.py

@@ -213,6 +213,11 @@ class Pickler:
         try:
             f = self.dispatch[t]
         except KeyError:
+            pid = self.inst_persistent_id(object)
+            if pid is not None:
+                self.save_pers(pid)
+                return
+
             try:
                 issc = issubclass(t, TypeType)
             except TypeError: # t is not a class
@@ -221,11 +226,6 @@ class Pickler:
                 self.save_global(object)
                 return
 
-            pid = self.inst_persistent_id(object)
-            if pid is not None:
-                self.save_pers(pid)
-                return
-
             try:
                 reduce = dispatch_table[t]
             except KeyError:

Modules/cPickle.c

@@ -2015,11 +2015,6 @@ save(Picklerobject *self, PyObject *args, int  pers_save)
 		}
 	}
 
-	if (PyType_IsSubtype(type, &PyType_Type)) {
-		res = save_global(self, args, NULL);
-		goto finally;
-	}
-
 	if (!pers_save && self->inst_pers_func) {
 		if ((tmp = save_pers(self, args, self->inst_pers_func)) != 0) {
 			res = tmp;
@@ -2027,6 +2022,11 @@ save(Picklerobject *self, PyObject *args, int  pers_save)
 		}
 	}
 
+	if (PyType_IsSubtype(type, &PyType_Type)) {
+		res = save_global(self, args, NULL);
+		goto finally;
+	}
+
 	if ((__reduce__ = PyDict_GetItem(dispatch_table, (PyObject *)type))) {
 		Py_INCREF(__reduce__);