From 74972b5ff4b011dc4761766a1dfcac82fda5c00b Mon Sep 17 00:00:00 2001
From: "5684185+vsariola@users.noreply.github.com"
 <5684185+vsariola@users.noreply.github.com>
Date: Sat, 7 Sep 2024 15:20:12 +0300
Subject: [PATCH] fix(tracker): ID collisions in ClearUnit and
 Instruments.unmarshal

---
 CHANGELOG.md      |  1 +
 tracker/action.go |  1 +
 tracker/list.go   | 10 ++++++----
 tracker/model.go  | 12 ++++++++++++
 4 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f8ccd03..100277a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   resized ([#145][i145])
 
 ### Fixed
+- Potential ID collisions when clearing unit or pasteing instruments
 - Assign new IDs to loaded instruments, and fix ID collisions in case they
   somehow still appear ([#146][i146])
 - In x86 templates, do not optimize away phase modulations when unisons are used
diff --git a/tracker/action.go b/tracker/action.go
index a1c2570..faa6f5b 100644
--- a/tracker/action.go
+++ b/tracker/action.go
@@ -154,6 +154,7 @@ func (m *Model) ClearUnit() Action {
 			defer (*Model)(m).change("DeleteUnitAction", PatchChange, MajorChange)()
 			m.d.UnitIndex = intMax(intMin(m.d.UnitIndex, len(m.d.Song.Patch[m.d.InstrIndex].Units)-1), 0)
 			m.d.Song.Patch[m.d.InstrIndex].Units[m.d.UnitIndex] = sointu.Unit{}
+			m.d.Song.Patch[m.d.InstrIndex].Units[m.d.UnitIndex].ID = m.maxID() + 1
 		},
 		allowed: func() bool {
 			return m.d.InstrIndex >= 0 &&
diff --git a/tracker/list.go b/tracker/list.go
index 644ff21..e765946 100644
--- a/tracker/list.go
+++ b/tracker/list.go
@@ -269,11 +269,13 @@ func (v *Instruments) unmarshal(data []byte) (from, to int, err error) {
 	if v.d.Song.Patch.NumVoices()+newInstr.Patch.NumVoices() > vm.MAX_VOICES {
 		return 0, 0, fmt.Errorf("InstrumentListView.unmarshal: too many voices: %d", v.d.Song.Patch.NumVoices()+newInstr.Patch.NumVoices())
 	}
-	patch := append(v.d.Song.Patch, make([]sointu.Instrument, len(newInstr.Patch))...)
+	v.d.Song.Patch = append(v.d.Song.Patch, make([]sointu.Instrument, len(newInstr.Patch))...)
 	sel := v.Selected()
-	copy(patch[sel+len(newInstr.Patch):], patch[sel:])
-	copy(patch[sel:sel+len(newInstr.Patch)], newInstr.Patch)
-	v.d.Song.Patch = patch
+	copy(v.d.Song.Patch[sel+len(newInstr.Patch):], v.d.Song.Patch[sel:])
+	for i := 0; i < len(newInstr.Patch); i++ {
+		(*Model)(v).assignUnitIDs(newInstr.Patch[i].Units)
+		v.d.Song.Patch[sel+i] = newInstr.Patch[i]
+	}
 	from = sel
 	to = sel + len(newInstr.Patch) - 1
 	return
diff --git a/tracker/model.go b/tracker/model.go
index f83e958..337f934 100644
--- a/tracker/model.go
+++ b/tracker/model.go
@@ -408,6 +408,18 @@ func (m *Model) send(message interface{}) {
 	m.modelMessages <- message
 }
 
+func (m *Model) maxID() int {
+	maxID := 0
+	for _, instr := range m.d.Song.Patch {
+		for _, unit := range instr.Units {
+			if unit.ID > maxID {
+				maxID = unit.ID
+			}
+		}
+	}
+	return maxID
+}
+
 func (m *Model) assignUnitIDs(units []sointu.Unit) {
 	maxId := 0
 	usedIds := make(map[int]bool)