+ _soloed_by_others_upstream += delta;
+ }
+
+ DEBUG_TRACE (DEBUG::Solo, string_compose ("%1 SbU delta %2 = %3 old = %4 sbd %5 ss %6 exclusive %7\n",
+ name(), delta, _soloed_by_others_upstream, old_sbu,
+ _soloed_by_others_downstream, _self_solo, Config->get_exclusive_solo()));
+
+ /* push the inverse solo change to everything that feeds us.
+
+ This is important for solo-within-group. When we solo 1 track out of N that
+ feed a bus, that track will cause mod_solo_by_upstream (+1) to be called
+ on the bus. The bus then needs to call mod_solo_by_downstream (-1) on all
+ tracks that feed it. This will silence them if they were audible because
+ of a bus solo, but the newly soloed track will still be audible (because
+ it is self-soloed).
+
+ but .. do this only when we are being told to solo-by-upstream (i.e delta = +1),
+ not in reverse.
+ */
+
+ if ((_self_solo || _soloed_by_others_downstream) &&
+ ((old_sbu == 0 && _soloed_by_others_upstream > 0) ||
+ (old_sbu > 0 && _soloed_by_others_upstream == 0))) {
+
+ if (delta > 0 || !Config->get_exclusive_solo()) {
+ DEBUG_TRACE (DEBUG::Solo, "\t ... INVERT push\n");
+ for (FedBy::iterator i = _fed_by.begin(); i != _fed_by.end(); ++i) {
+ boost::shared_ptr<Route> sr = i->r.lock();
+ if (sr) {
+ sr->mod_solo_by_others_downstream (-delta);
+ }
+ }
+ }
+ }