More robust plugin I/O mapping.

This does not change the actual mapping logic, but makes the application of
the mapping much more robust.  If there is no valid mapping for a given port,
that port is connected to silence (instead of crashing messily and/or via a
failed assertion).

Also tolerate mappings that nonsensically map to a buffer that is not present
(this particularly happens for MIDI ports in some cases) as a temporary fix.
The mapping logic needs work and/or our concept of just how much MIDI we support
in a route needs simplification...


git-svn-id: svn://localhost/ardour2/branches/3.0@10262 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 10 insertions, 3 deletions

diff --git a/libs/ardour/chan_mapping.cc b/libs/ardour/chan_mapping.cc
index 3f7ccad8f9..5c5bb17de6 100644
--- a/libs/ardour/chan_mapping.cc
+++ b/libs/ardour/chan_mapping.cc
@@ -41,12 +41,19 @@ ChanMapping::ChanMapping(ChanCount identity)
 }
 
 uint32_t
-ChanMapping::get(DataType t, uint32_t from)
+ChanMapping::get(DataType t, uint32_t from, bool* valid)
 {
 	Mappings::iterator tm = _mappings.find(t);
-	assert(tm != _mappings.end());
+	if (tm == _mappings.end()) {
+		*valid = false;
+		return -1;
+	}
 	TypeMapping::iterator m = tm->second.find(from);
-	assert(m != tm->second.end());
+	if (m == tm->second.end()) {
+		*valid = false;
+		return -1;
+	}
+	*valid = true;
 	return m->second;
 }