diff --git a/libs/ardour/ardour/event_ring_buffer.h b/libs/ardour/ardour/event_ring_buffer.h
index f8c8e005db..2ccb11dc2d 100644
--- a/libs/ardour/ardour/event_ring_buffer.h
+++ b/libs/ardour/ardour/event_ring_buffer.h
@@ -76,6 +76,8 @@ EventRingBuffer<Time>::peek (uint8_t* buf, size_t size)
 		return false;
 	}
 
+	assert (vec.len[0] > 0 || vec.len[1] > 0);
+
 	if (vec.len[0] > 0) {
 		memcpy (buf, vec.buf[0], std::min (vec.len[0], size));
 	}
diff --git a/libs/ardour/midi_model.cc b/libs/ardour/midi_model.cc
index c52ac4d2de..c65aeb2494 100644
--- a/libs/ardour/midi_model.cc
+++ b/libs/ardour/midi_model.cc
@@ -455,40 +455,34 @@ MidiModel::NoteDiffCommand::marshal_note(const NotePtr note)
 Evoral::Sequence<MidiModel::TimeType>::NotePtr
 MidiModel::NoteDiffCommand::unmarshal_note (XMLNode *xml_note)
 {
-	Evoral::event_id_t id;
+	Evoral::event_id_t id = -1;
 	if (!xml_note->get_property ("id", id)) {
 		error << "note information missing ID value" << endmsg;
-		id = -1;
 	}
 
-	uint8_t note;
+	uint8_t note = 127;
 	if (!xml_note->get_property("note", note)) {
 		warning << "note information missing note value" << endmsg;
-		note = 127;
 	}
 
-	uint8_t channel;
+	uint8_t channel = 0;
 	if (!xml_note->get_property("channel", channel)) {
 		warning << "note information missing channel" << endmsg;
-		channel = 0;
 	}
 
-	MidiModel::TimeType time;
+	MidiModel::TimeType time = MidiModel::TimeType();
 	if (!xml_note->get_property("time", time)) {
 		warning << "note information missing time" << endmsg;
-		time = MidiModel::TimeType();
 	}
 
-	MidiModel::TimeType length;
+	MidiModel::TimeType length = MidiModel::TimeType(1);
 	if (!xml_note->get_property("length", length)) {
 		warning << "note information missing length" << endmsg;
-		length = MidiModel::TimeType(1);
 	}
 
-	uint8_t velocity;
+	uint8_t velocity = 127;
 	if (!xml_note->get_property("velocity", velocity)) {
 		warning << "note information missing velocity" << endmsg;
-		velocity = 127;
 	}
 
 	NotePtr note_ptr(new Evoral::Note<TimeType>(channel, time, length, note, velocity));
diff --git a/libs/ardour/midi_ring_buffer.cc b/libs/ardour/midi_ring_buffer.cc
index dfe7d89f1b..3b811dfa58 100644
--- a/libs/ardour/midi_ring_buffer.cc
+++ b/libs/ardour/midi_ring_buffer.cc
@@ -147,7 +147,8 @@ MidiRingBuffer<T>::skip_to(samplepos_t start)
 	while (this->read_space() >= prefix_size) {
 
 		uint8_t peekbuf[prefix_size];
-		this->peek (peekbuf, prefix_size);
+		bool r = this->peek (peekbuf, prefix_size);
+		assert (r);
 
 		ev_time = *(reinterpret_cast<T*>((uintptr_t)peekbuf));
 		ev_size = *(reinterpret_cast<uint32_t*>((uintptr_t)(peekbuf + sizeof(T) + sizeof (Evoral::EventType))));
@@ -163,7 +164,7 @@ MidiRingBuffer<T>::skip_to(samplepos_t start)
 		this->increment_read_ptr (prefix_size);
 
 		uint8_t status;
-		bool r = this->peek (&status, sizeof(uint8_t));
+		r = this->peek (&status, sizeof(uint8_t));
 		assert (r); // If this failed, buffer is corrupt, all hope is lost
 
 		++count;
diff --git a/libs/ardour/tempo.cc b/libs/ardour/tempo.cc
index 77f7265717..68081d6707 100644
--- a/libs/ardour/tempo.cc
+++ b/libs/ardour/tempo.cc
@@ -3407,11 +3407,12 @@ TempoMap::gui_stretch_tempo (TempoSection* ts, const samplepos_t sample, const s
 		if (ts_copy->clamped()) {
 			TempoSection* next_t = next_tempo_section_locked (future_map, ts_copy);
 			TempoSection* prev_to_ts_copy = previous_tempo_section_locked (future_map, ts_copy);
+			assert (prev_to_ts_copy);
 			/* the change in samples is the result of changing the slope of at most 2 previous tempo sections.
 			 * constant to constant is straightforward, as the tempo prev to ts_copy has constant slope.
 			 */
 			double contribution = 0.0;
-			if (next_t && prev_to_ts_copy && prev_to_ts_copy->type() == TempoSection::Ramp) {
+			if (next_t && prev_to_ts_copy->type() == TempoSection::Ramp) {
 				contribution = (ts_copy->pulse() - prev_to_ts_copy->pulse()) / (double) (next_t->pulse() - prev_to_ts_copy->pulse());
 			}
 			samplepos_t const fr_off = end_sample - sample;
diff --git a/libs/vamp-plugins/TruePeak.cpp b/libs/vamp-plugins/TruePeak.cpp
index 3d6c12ee2a..9a9f6f93d8 100644
--- a/libs/vamp-plugins/TruePeak.cpp
+++ b/libs/vamp-plugins/TruePeak.cpp
@@ -18,6 +18,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include <assert.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -392,6 +393,7 @@ TruePeakdsp::process (float const *d, int n)
 
 	float x = 0;
 	float v;
+	assert (_buf);
 	float *b = _buf;
 	while (n--) {
 		v = fabsf(*b++);