set sync record's flags only after propagating new message

this is semantically cleaner, and fixes storing the flags in the rare
case that flags are not being synced and the target is not being
expunged, as in this case flags are queried only during the actual
propagation.

src/sync.c

@@ -262,7 +262,6 @@ match_tuids( sync_vars_t *svars, int t, message_t *msgs )
 			}
 			debug( "  -> TUID lost\n" );
 			jFprintf( svars, "& %u %u\n", srec->uid[M], srec->uid[S] );
-			srec->flags = 0;
 			// Note: status remains S_PENDING.
 			srec->tuid[0] = 0;
 			num_lost++;
@@ -942,7 +941,6 @@ load_state( sync_vars_t *svars )
 						break;
 					case '&':
 						debug( "TUID %." stringify(TUIDL) "s lost\n", srec->tuid );
-						srec->flags = 0;
 						srec->tuid[0] = 0;
 						break;
 					case '<':
@@ -1623,11 +1621,6 @@ box_loaded( int sts, message_t *msgs, int total_msgs, int recent_msgs, void *aux
 						debug( "  -> pair(%u,%u) created\n", srec->uid[M], srec->uid[S] );
 					}
 					if ((tmsg->flags & F_FLAGGED) || tmsg->size <= svars->chan->stores[t]->max_size) {
-						if (tmsg->flags != srec->flags) {
-							srec->flags = tmsg->flags;
-							jFprintf( svars, "* %u %u %u\n", srec->uid[M], srec->uid[S], srec->flags );
-							debug( "  -> updated flags to %u\n", tmsg->flags );
-						}
 						if (srec->status != S_PENDING) {
 							debug( "  -> not too big any more\n" );
 							srec->status = S_PENDING;
@@ -1845,6 +1838,11 @@ msg_copied( int sts, uint uid, copy_vars_t *vars )
 	sync_rec_t *srec = vars->srec;
 	switch (sts) {
 	case SYNC_OK:
+		if (vars->msg->flags != srec->flags) {
+			srec->flags = vars->msg->flags;
+			debug( "  -> updated flags to %u\n", srec->flags );
+			jFprintf( svars, "* %u %u %u\n", srec->uid[M], srec->uid[S], srec->flags );
+		}
 		if (!uid) {  // Stored to a non-UIDPLUS mailbox
 			svars->state[t] |= ST_FIND_NEW;
 		} else {