[vte/vte-0-36] emulation: Fix restricted scrolling with a short ring

[Christian Persch <chpe src gnome org>]

commit 98b54527c802620a5951a615fe6ae21ffc19a171
Author: Egmont Koblinger <egmont gmail com>
Date:   Tue Oct 22 23:56:05 2013 +0200

    emulation: Fix restricted scrolling with a short ring
    
    Fixes setting restrict scrolling with the upper bound being row 1 not working.
    To test, run "echo -e '\e[1;15r'"  immediately before the terminal starts
    scrolling; before this patch this had no effect.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=710483

 src/vteseq.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)
---
diff --git a/src/vteseq.c b/src/vteseq.c
index fad4d46..2ccd58e 100644
--- a/src/vteseq.c
+++ b/src/vteseq.c
@@ -1303,10 +1303,14 @@ vte_sequence_handler_cs (VteTerminal *terminal, GValueArray *params)
        screen->scrolling_region.start = start;
        screen->scrolling_region.end = end;
        screen->scrolling_restricted = TRUE;
-       /* Special case -- run wild, run free. */
        if (screen->scrolling_region.start == 0 &&
            screen->scrolling_region.end == rows - 1) {
+               /* Special case -- run wild, run free. */
                screen->scrolling_restricted = FALSE;
+       } else {
+               /* Maybe extend the ring -- bug 710483 */
+               while (_vte_ring_next(screen->row_data) < screen->insert_delta + rows)
+                       _vte_ring_insert(screen->row_data, _vte_ring_next(screen->row_data));
        }
 }
 
@@ -1339,11 +1343,15 @@ vte_sequence_handler_cS (VteTerminal *terminal, GValueArray *params)
        screen->scrolling_region.start = start;
        screen->scrolling_region.end = end;
        screen->scrolling_restricted = TRUE;
-       /* Special case -- run wild, run free. */
        rows = terminal->row_count;
        if ((screen->scrolling_region.start == 0) &&
            (screen->scrolling_region.end == rows - 1)) {
+               /* Special case -- run wild, run free. */
                screen->scrolling_restricted = FALSE;
+       } else {
+               /* Maybe extend the ring -- bug 710483 */
+               while (_vte_ring_next(screen->row_data) < screen->insert_delta + rows)
+                       _vte_ring_insert(screen->row_data, _vte_ring_next(screen->row_data));
        }
        /* Clamp the cursor to the scrolling region. */
        screen->cursor_current.row = CLAMP(screen->cursor_current.row,