[vte/wip/egmont/bidi: 29/78] crash fix

[Egmont Koblinger <egmontkob src gnome org>]

commit d3e7aace1a8a12c0399d0e554e0545e57f03db15
Author: Egmont Koblinger <egmont gmail com>
Date:   Thu Aug 23 21:58:52 2018 +0200

    crash fix

 src/bidi.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/bidi.cc b/src/bidi.cc
index 7fb67bae..e1657b88 100644
--- a/src/bidi.cc
+++ b/src/bidi.cc
@@ -231,8 +231,8 @@ long RingView::find_paragraph(long row)
         const VteRowData *row_data;
 
         while (row-- > row_stop) {
-                if (row == -1)
-                        return 0;
+                if (row < _vte_ring_delta(m_ring))
+                        return row + 1;
                 row_data = m_ring->index(row);
                 if (row_data == nullptr || !row_data->attr.soft_wrapped)
                         return row + 1;