make handling of sends-only feed-based solo propagation symmetrical upstream and downstream (fixes #4252) and add more DEBUG::Solo tracing for future aid

git-svn-id: svn://localhost/ardour2/branches/3.0@9972 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 37 insertions, 8 deletions

diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 631a20aac7..e735eca8e7 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -2309,6 +2309,8 @@ Session::route_solo_isolated_changed (void* /*src*/, boost::weak_ptr<Route> wpr)
 void
 Session::route_solo_changed (bool self_solo_change, void* /*src*/, boost::weak_ptr<Route> wpr)
 {
+	DEBUG_TRACE (DEBUG::Solo, string_compose ("route solo change, self = %1\n", self_solo_change));
+
 	if (!self_solo_change) {
 		// session doesn't care about changes to soloed-by-others
 		return;
@@ -2316,16 +2318,12 @@ Session::route_solo_changed (bool self_solo_change, void* /*src*/, boost::weak_p
 
 	if (solo_update_disabled) {
 		// We know already
+		DEBUG_TRACE (DEBUG::Solo, "solo update disabled - changed ignored\n");
 		return;
 	}
 
 	boost::shared_ptr<Route> route = wpr.lock ();
-
-	if (!route) {
-		/* should not happen */
-		error << string_compose (_("programming error: %1"), X_("invalid route weak ptr passed to route_solo_changed")) << endmsg;
-		return;
-	}
+	assert (route);
 
 	boost::shared_ptr<RouteList> r = routes.reader ();
 	int32_t delta;
@@ -2352,10 +2350,14 @@ Session::route_solo_changed (bool self_solo_change, void* /*src*/, boost::weak_p
 		}
 	}
 
+	DEBUG_TRACE (DEBUG::Solo, string_compose ("propagate solo change, delta = %1\n", delta));
+
 	solo_update_disabled = true;
 
 	RouteList uninvolved;
 
+	DEBUG_TRACE (DEBUG::Solo, string_compose ("%1\n", route->name()));
+
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 		bool via_sends_only;
 		bool in_signal_flow;
@@ -2367,18 +2369,42 @@ Session::route_solo_changed (bool self_solo_change, void* /*src*/, boost::weak_p
 
 		in_signal_flow = false;
 
+		DEBUG_TRACE (DEBUG::Solo, string_compose ("check feed from %1\n", (*i)->name()));
+		
 		if ((*i)->feeds (route, &via_sends_only)) {
 			if (!via_sends_only) {
 				if (!route->soloed_by_others_upstream()) {
 					(*i)->mod_solo_by_others_downstream (delta);
 				}
-				in_signal_flow = true;
 			}
+			in_signal_flow = true;
+		} else {
+			DEBUG_TRACE (DEBUG::Solo, "\tno feed from\n");
 		}
+		
+		DEBUG_TRACE (DEBUG::Solo, string_compose ("check feed to %1\n", (*i)->name()));
 
 		if (route->feeds (*i, &via_sends_only)) {
-			(*i)->mod_solo_by_others_upstream (delta);
+			/* propagate solo upstream only if routing other than
+			   sends is involved, but do consider the other route
+			   (*i) to be part of the signal flow even if only
+			   sends are involved.
+			*/
+			DEBUG_TRACE (DEBUG::Solo, string_compose ("%1 feeds %2 via sends only %3 sboD %4 sboU %5\n",
+								  route->name(),
+								  (*i)->name(),
+								  via_sends_only,
+								  route->soloed_by_others_downstream(),
+								  route->soloed_by_others_upstream()));
+			if (!via_sends_only) {
+				if (!route->soloed_by_others_downstream()) {
+					DEBUG_TRACE (DEBUG::Solo, string_compose ("\tmod %1 by %2\n", (*i)->name(), delta));
+					(*i)->mod_solo_by_others_upstream (delta);
+				}
+			}
 			in_signal_flow = true;
+		} else {
+			DEBUG_TRACE (DEBUG::Solo, "\tno feed to\n");
 		}
 
 		if (!in_signal_flow) {
@@ -2387,6 +2413,8 @@ Session::route_solo_changed (bool self_solo_change, void* /*src*/, boost::weak_p
 	}
 
 	solo_update_disabled = false;
+	DEBUG_TRACE (DEBUG::Solo, "propagation complete\n");
+
 	update_route_solo_state (r);
 
 	/* now notify that the mute state of the routes not involved in the signal
@@ -2394,6 +2422,7 @@ Session::route_solo_changed (bool self_solo_change, void* /*src*/, boost::weak_p
 	*/
 
 	for (RouteList::iterator i = uninvolved.begin(); i != uninvolved.end(); ++i) {
+		DEBUG_TRACE (DEBUG::Solo, string_compose ("mute change for %1\n", (*i)->name()));
 		(*i)->mute_changed (this);
 	}