From b8f1241bca274c6a087ce0f5ac586bd873c5857c Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Tue, 23 Jul 2013 10:38:54 -0500
Subject: [PATCH] fix scrolling glitch.

---
 lib/widget.js | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/lib/widget.js b/lib/widget.js
index 0d434c7..222d1af 100644
--- a/lib/widget.js
+++ b/lib/widget.js
@@ -3243,7 +3243,8 @@ ScrollableBox.prototype.scroll = function(offset, always) {
     , i
     , max
     , emax
-    , t;
+    , t
+    , l;
 
   if (diff === 0) {
     return this.emit('scroll');
@@ -3257,6 +3258,7 @@ ScrollableBox.prototype.scroll = function(offset, always) {
   max = this._clines.length - (this.height - this.iheight);
   if (max < 0) max = 0;
   emax = this._scrollBottom() - (this.height - this.iheight);
+  if (emax < 0) emax = 0;
 
   this.childBase = Math.min(this.childBase, Math.max(emax, max));
   diff = this.childBase - base;
@@ -3268,13 +3270,13 @@ ScrollableBox.prototype.scroll = function(offset, always) {
   }
 
   if (diff > 0) {
-    for (i = base; i < this.childBase; i++) {
-      if (!this._clines[i]) continue;
+    l = Math.min(this.childBase, this._clines.length);
+    for (i = base; i < l; i++) {
       this.contentIndex += this._clines[i].length + 1;
     }
   } else {
-    for (i = base - 1; i >= this.childBase; i--) {
-      if (!this._clines[i]) continue;
+    l = Math.min(this.childBase, this._clines.length);
+    for (i = base - 1; i >= l; i--) {
       this.contentIndex -= this._clines[i].length + 1;
     }
   }
@@ -3300,9 +3302,9 @@ ScrollableBox.prototype.scroll = function(offset, always) {
 };
 
 ScrollableBox.prototype._recalculateIndex = function() {
-  var max, emax, i, t;
+  var max, emax, i, t, l;
 
-  if (this.detached || !this.scrollabe) {
+  if (this.detached || !this.scrollable) {
     this.contentIndex = 0;
     return 0;
   }
@@ -3310,6 +3312,7 @@ ScrollableBox.prototype._recalculateIndex = function() {
   max = this._clines.length - (this.height - this.iheight);
   if (max < 0) max = 0;
   emax = this._scrollBottom() - (this.height - this.iheight);
+  if (emax < 0) emax = 0;
 
   this.childBase = Math.min(this.childBase, Math.max(emax, max));
 
@@ -3319,8 +3322,8 @@ ScrollableBox.prototype._recalculateIndex = function() {
     this.childBase = this.baseLimit;
   }
 
-  for (i = 0, t = 0; i < this.childBase; i++) {
-    if (!this._clines[i]) continue;
+  l = Math.min(this.childBase, this._clines.length);
+  for (i = 0, t = 0; i < l; i++) {
     t += this._clines[i].length + 1;
   }
 
@@ -4215,8 +4218,8 @@ Textarea.prototype._listener = function(ch, key) {
 
 Textarea.prototype._typeScroll = function() {
   // XXX Workaround
-  var width = this.height - this.iheight;
-  if (this._clines.length - this.childBase > width) {
+  var height = this.height - this.iheight;
+  if (this._clines.length - this.childBase > height) {
     //this.setContent(this.value + '\n');
     this.scroll(this._clines.length);
   }