[vte/vte-next] Bug 708496 - Lines disappear after positioning back the cursor

[Behdad Esfahbod <behdad src gnome org>]

commit 0a5c8f24e00e368d9648b3eba2f13dca77fa324d
Author: Behdad Esfahbod <behdad behdad org>
Date:   Fri Sep 27 17:43:18 2013 -0400

    Bug 708496 - Lines disappear after positioning back the cursor
    
    Patch from Egmont Koblinger.

 src/ring.c |   23 +++++++++++++++++++----
 1 files changed, 19 insertions(+), 4 deletions(-)
---
diff --git a/src/ring.c b/src/ring.c
index 0acb0a0..e084c7d 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -258,17 +258,32 @@ _vte_ring_thaw_row (VteRing *ring, gulong position, VteRowData *row, gboolean do
        }
 
        if (do_truncate) {
-               if (records[0].text_start_offset < ring->last_attr_text_start_offset) {
-                       if (_vte_stream_read (ring->attr_stream, records[0].attr_start_offset, (char *) 
&attr_change, sizeof (attr_change))) {
-                               ring->last_attr_text_start_offset = attr_change.text_end_offset;
+               gsize attr_stream_truncate_at = records[0].attr_start_offset;
+               _vte_debug_print (VTE_DEBUG_RING, "Truncating\n");
+               if (records[0].text_start_offset <= ring->last_attr_text_start_offset) {
+                       /* Check the previous attr record. If its text ends where truncating, this attr 
record also needs to be removed. */
+                       if (_vte_stream_read (ring->attr_stream, attr_stream_truncate_at - sizeof 
(attr_change), (char *) &attr_change, sizeof (attr_change))) {
+                               if (records[0].text_start_offset == attr_change.text_end_offset) {
+                                       _vte_debug_print (VTE_DEBUG_RING, "... at attribute change\n");
+                                       attr_stream_truncate_at -= sizeof (attr_change);
+                               }
+                       }
+                       /* Reconstruct last_attr from the first record of attr_stream that we cut off,
+                          last_attr_text_start_offset from the last record that we keep. */
+                       if (_vte_stream_read (ring->attr_stream, attr_stream_truncate_at, (char *) 
&attr_change, sizeof (attr_change))) {
                                ring->last_attr = attr_change.attr;
+                               if (_vte_stream_read (ring->attr_stream, attr_stream_truncate_at - sizeof 
(attr_change), (char *) &attr_change, sizeof (attr_change))) {
+                                       ring->last_attr_text_start_offset = attr_change.text_end_offset;
+                               } else {
+                                       ring->last_attr_text_start_offset = 0;
+                               }
                        } else {
                                ring->last_attr_text_start_offset = 0;
                                ring->last_attr.i = basic_cell.i.attr;
                        }
                }
                _vte_stream_truncate (ring->row_stream, position * sizeof (record));
-               _vte_stream_truncate (ring->attr_stream, records[0].attr_start_offset);
+               _vte_stream_truncate (ring->attr_stream, attr_stream_truncate_at);
                _vte_stream_truncate (ring->text_stream, records[0].text_start_offset);
        }
 }