Fix custom recursive loading in post_load callback

Before we called the callback while holding the statements locked. As a
result, if the callback tried to load another object of this type, it
failed. Now we unlock the statements (since we have completely loaded
the object from ODB's point of view) and then call the callback. The
callback test has been updated to test this situation.

1 files changed, 25 insertions, 4 deletions

diff --git a/common/callback/driver.cxx b/common/callback/driver.cxx
index 4179168..fc67aac 100644
--- a/common/callback/driver.cxx
+++ b/common/callback/driver.cxx
@@ -34,9 +34,17 @@ const char* events[] =
 };
 
 void object::
-db_callback (callback_event e, database&)
+db_callback (callback_event e, database& db)
 {
   cout << "  " << events[e] << " " << id_ << endl;
+
+  // Test custom recursive loading.
+  //
+  if (e == callback_event::post_load && ref != 0)
+  {
+    robj = db.load<object> (ref);
+    cout << "    " << id_ << ' ' << ref << ' ' << robj->id_ << endl;
+  }
 }
 
 void object::
@@ -132,23 +140,36 @@ main (int argc, char* argv[])
       {
         object o1 (1, 1);
         object o2 (2, 2);
-        object o3 (3, 2);
+        object o3 (3, 3);
+        object o4 (4, 4);
 
         o1.pobj = &o2;
+        o1.ref = 4;
+
         o2.pobj = &o3;
+        o2.ref = 4;
 
         transaction t (db->begin ());
         db->persist (o1);
         db->persist (o2);
         db->persist (o3);
+        db->persist (o4);
         t.commit ();
       }
 
       {
         transaction t (db->begin ());
         auto_ptr<object> o1 (db->load<object> (1));
-        delete o1->pobj->pobj;
-        delete o1->pobj;
+        object* o2 (o1->pobj);
+
+        cout << o1->id_ << ' ' << o1->ref << ' ' << o1->robj->id_ << endl;
+        cout << o2->id_ << ' ' << o2->ref << ' ' << o2->robj->id_ << endl;
+
+        delete o1->robj;
+        delete o2->robj;
+
+        delete o2->pobj;
+        delete o2;
         t.commit ();
       }
     }