R-1278: the install page says when a backup of an earlier install is kept and links the restore page (HU and EN). Red-proved. Commit only.

controller/internal/backup/unit_owner.go

@@ -240,6 +240,26 @@ func (m *Manager) driveOfNamespace(nsRoot string) string {
 	return nsRoot
 }
 
+// KeptBackupsFor (R-1278) counts the backups of an EARLIER install of stack that the box keeps: its set-aside units
+// (D47) and the unit „remove — keep backups" left (a removed app's). The install page names them beside a fresh start.
+func (m *Manager) KeptBackupsFor(stack string) int {
+	if m == nil || !validMirrorStackName(stack) {
+		return 0
+	}
+	n := 0
+	if m.settings != nil {
+		for _, k := range m.settings.GetKeptCopies() {
+			if k.Kind == KeptKindUnit && k.Source == stack {
+				n++
+			}
+		}
+	}
+	if _, ok := m.RemovedAppUnitFor(stack); ok {
+		n++
+	}
+	return n
+}
+
 // SetAsideDirsForApp lists the app's set-aside folders (<root>/backups/set-aside/<stack>) that exist, on every
 // namespace root a unit of it can sit on.
 func (m *Manager) SetAsideDirsForApp(stack string) []string {

controller/internal/backup/unit_owner_test.go

@@ -373,3 +373,21 @@ func TestR1288_ARestoreOfASetAsideUnitRetiresTheReplacedUnitQuietly(t *testing.T
 		t.Fatalf("the next backup set something aside again: alarms %v, set-aside %v", alarms, r.setAside(t))
 	}
 }
+
+// R-1278: the install page's count of an earlier install's kept backups — a set-aside unit counts once per copy.
+func TestR1278_KeptBackupsForCountsTheSetAsideUnits(t *testing.T) {
+	r := d47Setup(t, "aaaa000000000001")
+	if n := r.m.KeptBackupsFor("tandoor"); n != 0 {
+		t.Fatalf("before any set-aside: %d", n)
+	}
+	r.reinstall("bbbb000000000002")
+	if err := r.m.captureRecoveryUnit("tandoor", false); err != nil {
+		t.Fatal(err)
+	}
+	if n := r.m.KeptBackupsFor("tandoor"); n != 1 {
+		t.Fatalf("after one set-aside: %d, want 1", n)
+	}
+	if n := r.m.KeptBackupsFor("other"); n != 0 {
+		t.Fatalf("another app counts nothing: %d", n)
+	}
+}