restic: let a restore point taken by hand go only after a night recorded good, say a missing hand= as a file to push, and say what a failed thinning already let go (novox/hq issue 453)

modules/restic/cmd/restic-backups/backups.go

@@ -379,6 +379,9 @@ func (b *Backups) backUp(ctx context.Context, only string, hand bool) (map[strin
 	for _, d := range chosen {
 		outcome[d.Module] = b.one(ctx, d, hand)
 		b.record(d.Module, outcome[d.Module])
+		if n := outcome[d.Module]; !hand && n.OK && n.Snapshot != "" {
+			b.recordGoodNight(d.Module, n.Snapshot)
+		}
 	}
 	// A retention that does not read thins nothing: keeping too much costs space, thinning by a value
 	// nobody meant loses restore points (novox/hq issue 416).
@@ -388,8 +391,13 @@ func (b *Backups) backUp(ctx context.Context, only string, hand bool) (map[strin
 		thinned.Refused = err.Error()
 		b.Say("the retention does not read, so nothing is thinned and every restore point is kept: %v", err)
 	} else if letGo, err := b.thin(ctx, keep); err != nil {
-		thinned.Kept, thinned.Error = &keep, err.Error()
-		b.Say("thinning the restore points failed, and every one is kept: %v", err)
+		thinned.Kept, thinned.Error, thinned.LetGo = &keep, err.Error(), letGo
+		if len(letGo) > 0 {
+			b.Say("thinning the restore points failed after letting go %s, taken by hand; every other one is kept: %v",
+				strings.Join(letGo, ", "), err)
+		} else {
+			b.Say("thinning the restore points failed, and every one is kept: %v", err)
+		}
 	} else {
 		thinned.Kept, thinned.OK, thinned.LetGo = &keep, true, letGo
 	}
@@ -400,7 +408,7 @@ func (b *Backups) backUp(ctx context.Context, only string, hand bool) (map[strin
 
 // thin forgets the restore points taken by hand that are past their days and have a later night of their
 // module, by id, then thins the rest by the counts, keeping every one still tagged as taken by hand (novox/hq
-// issue 453). It answers the short ids it let go. A list that does not read thins nothing: a restore point
+// issue 453). It answers the short ids it let go — on an error of the counts' thinning too, for those are gone. A list that does not read thins nothing: a restore point
 // taken by hand is never lost to a list nobody could read.
 func (b *Backups) thin(ctx context.Context, keep Retention) ([]string, error) {
 	snaps, err := b.Snapshots(ctx, "")
@@ -408,7 +416,7 @@ func (b *Backups) thin(ctx context.Context, keep Retention) ([]string, error) {
 		return nil, fmt.Errorf("the restore points could not be listed: %w", err)
 	}
 	var ids, letGo []string
-	for _, s := range handLetGo(snaps, b.Now(), keep.Hand) {
+	for _, s := range handLetGo(snaps, b.GoodNights(), b.Now(), keep.Hand) {
 		ids, letGo = append(ids, s.ID), append(letGo, s.ShortID)
 	}
 	if len(ids) > 0 {
@@ -524,6 +532,7 @@ func (b *Backups) BackedUp(ctx context.Context, module string) ([]ModuleBackups,
 	measured := b.Measurements()
 	snaps, _ := b.Snapshots(ctx, module)
 	inForce := b.inForce(ctx)
+	goodNights := b.GoodNights()
 	thinned := b.LastRun().Thinned
 	out := []ModuleBackups{}
 	listed := map[string]bool{}
@@ -534,7 +543,7 @@ func (b *Backups) BackedUp(ctx context.Context, module string) ([]ModuleBackups,
 		listed[d.Module] = true
 		m := ModuleBackups{Module: d.Module, Runs: len(d.Runs), Paths: d.Paths, Retention: inForce, Thinned: thinned,
 			Data:      itemReports(items[d.Module], measured[d.Module], d.Paths, good[d.Module]),
-			HandTaken: handKept(d.Module, snaps, inForce)}
+			HandTaken: handKept(d.Module, snaps, goodNights, inForce)}
 		if n, ok := nights[d.Module]; ok {
 			m.LastNight = &n
 		}