sort: new `flagged` sorting criteria

Add new `flagged` criteria to `:sort` command (and apparently to the
`sort` config option). Good for moving important stuff up.

Signed-off-by: Vitaly Ovchinnikov <v@postbox.nz>
Reviewed-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>

1 files changed, 2 insertions, 0 deletions

diff --git a/lib/sort/sort.go b/lib/sort/sort.go
index 287f986c..082ba48b 100644
--- a/lib/sort/sort.go
+++ b/lib/sort/sort.go
@@ -51,6 +51,8 @@ func parseSortField(arg string) (types.SortField, error) {
 		return types.SortSubject, nil
 	case "to":
 		return types.SortTo, nil
+	case "flagged":
+		return types.SortFlagged, nil
 	default:
 		return types.SortArrival, fmt.Errorf("%v is not a valid sort criterion", arg)
 	}