lib/model: Properly handle deleting multiple files when doing scans with subs (fixes #2851)

lib/db/leveldb_dbinstance.go

@@ -236,14 +236,11 @@ func (db *Instance) updateFiles(folder, device []byte, fs []protocol.FileInfo, l
 	return maxLocalVer
 }
 
-func (db *Instance) withHave(folder, device []byte, truncate bool, fn Iterator) {
-	start := db.deviceKey(folder, device, nil)                            // before all folder/device files
-	limit := db.deviceKey(folder, device, []byte{0xff, 0xff, 0xff, 0xff}) // after all folder/device files
-
+func (db *Instance) withHave(folder, device, prefix []byte, truncate bool, fn Iterator) {
 	t := db.newReadOnlyTransaction()
 	defer t.close()
 
-	dbi := t.NewIterator(&util.Range{Start: start, Limit: limit}, nil)
+	dbi := t.NewIterator(util.BytesPrefix(db.deviceKey(folder, device, prefix)[:1+64+32+len(prefix)]), nil)
 	defer dbi.Release()
 
 	for dbi.Next() {

lib/db/set.go

@@ -171,14 +171,18 @@ func (s *FileSet) WithNeedTruncated(device protocol.DeviceID, fn Iterator) {
 
 func (s *FileSet) WithHave(device protocol.DeviceID, fn Iterator) {
 	l.Debugf("%s WithHave(%v)", s.folder, device)
-	s.db.withHave([]byte(s.folder), device[:], false, nativeFileIterator(fn))
+	s.db.withHave([]byte(s.folder), device[:], nil, false, nativeFileIterator(fn))
 }
 
 func (s *FileSet) WithHaveTruncated(device protocol.DeviceID, fn Iterator) {
 	l.Debugf("%s WithHaveTruncated(%v)", s.folder, device)
-	s.db.withHave([]byte(s.folder), device[:], true, nativeFileIterator(fn))
+	s.db.withHave([]byte(s.folder), device[:], nil, true, nativeFileIterator(fn))
 }
 
+func (s *FileSet) WithPrefixedHaveTruncated(device protocol.DeviceID, prefix string, fn Iterator) {
+	l.Debugf("%s WithPrefixedHaveTruncated(%v)", s.folder, device)
+	s.db.withHave([]byte(s.folder), device[:], []byte(prefix), true, nativeFileIterator(fn))
+}
 func (s *FileSet) WithGlobal(fn Iterator) {
 	l.Debugf("%s WithGlobal()", s.folder)
 	s.db.withGlobal([]byte(s.folder), nil, false, nativeFileIterator(fn))