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, 16 insertions, 0 deletions

diff --git a/odb/mysql/object-statements.hxx b/odb/mysql/object-statements.hxx
index c341352..3f3196d 100644
--- a/odb/mysql/object-statements.hxx
+++ b/odb/mysql/object-statements.hxx
@@ -74,6 +74,22 @@ namespace odb
       {
       }
 
+      struct auto_unlock
+      {
+        // Unlocks the statement on construction and re-locks it on
+        // destruction.
+        //
+        auto_unlock (object_statements_base&);
+        ~auto_unlock ();
+
+      private:
+        auto_unlock (const auto_unlock&);
+        auto_unlock& operator= (const auto_unlock&);
+
+      private:
+        object_statements_base& s_;
+      };
+
     protected:
       connection_type& conn_;
       bool locked_;