From 8f989eeadddd06762f229a37bfb6cfc5510fa9e3 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Sat, 27 Jul 2013 05:49:53 -0500
Subject: [PATCH] fix scrollbar arithmetic.

---
 lib/widget.js | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/widget.js b/lib/widget.js
index c0df1fb..5d2832e 100644
--- a/lib/widget.js
+++ b/lib/widget.js
@@ -2838,17 +2838,19 @@ Element.prototype.render = function() {
 
   // Draw the scrollbar.
   if (this.scrollbar) {
-    i = Math.max(this._clines.length + 1,
-      this._scrollBottom() + (yl - yi) + 1);
+    i = Math.max(this._clines.length, this._scrollBottom());
   }
   if (coords.notop || coords.nobot) i = -Infinity;
   if (this.scrollbar && (yl - yi) < i) {
-    i -= yl - yi;
     x = xl - 1;
     if (this.scrollbar.ignoreBorder && this.border) x++;
-    y = this.childBase + this.childOffset;
-    y = y / i;
+    if (this.alwaysScroll) {
+      y = this.childBase / (i - (yl - yi));
+    } else {
+      y = (this.childBase + this.childOffset) / i;
+    }
     y = yi + ((yl - yi) * y | 0);
+    if (y >= yl) y = yl - 1;
     cell = lines[y] && lines[y][x];
     if (cell) {
       ch = this.scrollbar.ch || ' ';