quick checks on empty control lists, to avoid unnecessary work

diff --git a/libs/ardour/session_rtevents.cc b/libs/ardour/session_rtevents.cc
index 8dba60f0e5cbe0017d423d80c2bad63d96a29b09..f1f99e369373e3dda0e9380482cae287f6001d55 100644 (file)
--- a/libs/ardour/session_rtevents.cc
+++ b/libs/ardour/session_rtevents.cc
@@ -37,6 +37,10 @@ using namespace Glib;
 void
 Session::set_controls (boost::shared_ptr<ControlList> cl, double val, Controllable::GroupControlDisposition gcd)
 {
+       if (cl->empty()) {
+               return;
+       }
+
        std::cerr << "Session::set_controls called on " << cl->size() << " controls, group = " << enum_2_string (gcd) << std::endl;
 
        for (ControlList::iterator ci = cl->begin(); ci != cl->end(); ++ci) {
@@ -50,6 +54,10 @@ Session::set_controls (boost::shared_ptr<ControlList> cl, double val, Controllab
 void
 Session::set_control (boost::shared_ptr<AutomationControl> ac, double val, Controllable::GroupControlDisposition gcd)
 {
+       if (!ac) {
+               return;
+       }
+
        boost::shared_ptr<ControlList> cl (new ControlList);
        cl->push_back (ac);
        set_controls (cl, val, gcd);