Fix a bug in scroll_display(): when the scrolled region contains the cursor

we need to update dispcurs as well as disptext.

Add scroll optimisation to scroll().  This makes it rather obvious that scroll
optimisation is breaking with PuTTY's usual policy of lazy updates, since
scrolling is done eagerly.  Fixing this so that all the scrolling is saved
up for do_paint would be nice, but non-trivial.

[originally from svn r2252]

diff --git a/terminal.c b/terminal.c
index 8b48a3c58135c3a2a60d6e86b91e41fbbfdfdc91..06d6ee6b44a5610750ea9e1892d59c8d1f433aaa 100644 (file)
--- a/terminal.c
+++ b/terminal.c
@@ -592,11 +592,13 @@ static void check_selection(Terminal *term, pos from, pos to)
 static void scroll(Terminal *term, int topline, int botline, int lines, int sb)
 {
     unsigned long *line, *line2;
-    int i, seltop;
+    int i, seltop, olddisptop, shift;
 
     if (topline != 0 || term->alt_which != 0)
        sb = FALSE;
 
+    olddisptop = term->disptop;
+    shift = lines;
     if (lines < 0) {
        while (lines < 0) {
            line = delpos234(term->screen, botline);
@@ -705,6 +707,11 @@ static void scroll(Terminal *term, int topline, int botline, int lines, int sb)
            lines--;
        }
     }
+#ifdef OPTIMISE_SCROLL
+    shift += term->disptop - olddisptop;
+    if (shift < term->rows && shift > -term->rows && shift != 0)
+       scroll_display(term, topline, botline, shift);
+#endif /* OPTIMISE_SCROLL */
 }
 
 #ifdef OPTIMISE_SCROLL
@@ -722,10 +729,15 @@ static void scroll_display(Terminal *term, int topline, int botline, int lines)
     size = end - start - distance;
     if (lines > 0) {
        memmove(start, start + distance, size * TSIZE);
+       if (term->dispcurs >= start + distance &&
+           term->dispcurs <= start + distance + size)
+           term->dispcurs -= distance;
        for (i = 0; i < distance; i++)
            (start + size)[i] |= ATTR_INVALID;
     } else {
        memmove(start + distance, start, size * TSIZE);
+       if (term->dispcurs >= start && term->dispcurs <= start + size)
+           term->dispcurs += distance;
        for (i = 0; i < distance; i++)
            start[i] |= ATTR_INVALID;
     }