[vte] Revert "emulation: Make clear compatible with xterm, don't add lines to scrollback"

[Egmont Koblinger <egmontkob src gnome org>]

commit 6e369a5d6e5d21dd6242b362c15a7c634483b0dc
Author: Egmont Koblinger <egmont gmail com>
Date:   Thu Apr 2 01:00:07 2015 +0200

    Revert "emulation: Make clear compatible with xterm, don't add lines to scrollback"
    
    This reverts commit 450bf257266c1ec0f380e88a5512743acc6fc863.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=747191

 src/vteseq.c |   29 ++++++++++++-----------------
 1 files changed, 12 insertions(+), 17 deletions(-)
---
diff --git a/src/vteseq.c b/src/vteseq.c
index 1910612..80c4e65 100644
--- a/src/vteseq.c
+++ b/src/vteseq.c
@@ -287,25 +287,20 @@ _vte_terminal_home_cursor (VteTerminal *terminal)
 static void
 _vte_terminal_clear_screen (VteTerminal *terminal)
 {
-        long i;
-        VteRowData *rowdata;
+       long i, initial, row;
        VteScreen *screen;
        screen = terminal->pvt->screen;
-
-        for (i = 0; i < terminal->pvt->row_count; i++) {
-                /* If the row is actually on the screen, clear data in the row. */
-                if (_vte_ring_next(screen->row_data) > screen->insert_delta + i) {
-                        /* Get the data for the row. */
-                        rowdata = _vte_ring_index_writable (screen->row_data, screen->insert_delta + i);
-                        g_assert(rowdata != NULL);
-                        /* Remove it. */
-                        _vte_row_data_shrink (rowdata, 0);
-                        /* Add enough cells to the end of the line to fill out the row. */
-                        _vte_row_data_fill (rowdata, &terminal->pvt->fill_defaults, 
terminal->pvt->column_count);
-                        rowdata->attr.soft_wrapped = 0;
-                }
-        }
-
+       initial = screen->insert_delta;
+        row = terminal->pvt->cursor.row - screen->insert_delta;
+       initial = _vte_ring_next(screen->row_data);
+       /* Add a new screen's worth of rows. */
+       for (i = 0; i < terminal->pvt->row_count; i++)
+               _vte_terminal_ring_append (terminal, TRUE);
+       /* Move the cursor and insertion delta to the first line in the
+        * newly-cleared area and scroll if need be. */
+       screen->insert_delta = initial;
+        terminal->pvt->cursor.row = row + screen->insert_delta;
+       _vte_terminal_adjust_adjustments(terminal);
        /* Redraw everything. */
        _vte_invalidate_all(terminal);
        /* We've modified the display.  Make a note of it. */