Fixed abort of e.g. comp when draft folder is empty.

In this case mp->lowoff is 1 but mp->lowmsg equal mp->hghmsg equal 0.
Hence we have an access at mp->msgstats[-1], which corrupted our mem.
Gdb hadn't helped me for this, but valgrind showed me the problem.

diff --git a/sbr/seq_add.c b/sbr/seq_add.c
index 5d0987c..6c99b5d 100644 (file)
--- a/sbr/seq_add.c
+++ b/sbr/seq_add.c
@@ -156,7 +156,7 @@ seq_addmsg(struct msgs *mp, char *cp, int msgnum, int public, int zero)
        ** If sequence is new, or zero flag is set, then first
        ** clear the bit for this sequence from all messages.
        */
-       if (new_seq || zero) {
+       if (mp->nummsg>0 && (new_seq || zero)) {
                for (j = mp->lowmsg; j <= mp->hghmsg; j++)
                        clear_sequence(mp, i, j);
        }