improve charWidth and strWidth.

lib/unicode.js

@@ -118,6 +118,21 @@ exports.charWidth = function(str, i) {
   // nul
   if (point === 0) return 0;
 
+  // tab
+  if (point === 0x09) {
+    if (!exports.blessed) {
+      exports.blessed = require('../');
+    }
+    return exports.blessed.screen.global
+      ? exports.blessed.screen.global.tabc.length
+      : 8;
+  }
+
+  // 8-bit control characters (2-width according to unicode??)
+  if (point < 32 || (point >= 0x7f && point < 0xa0)) {
+    return 0;
+  }
+
   // search table of non-spacing characters
   // is ucs combining or C0/C1 control character
   if (exports.combining[point]) {

lib/widget.js

@@ -5972,9 +5972,9 @@ Textarea.prototype._updateCursor = function(get) {
 };
 
 Textarea.prototype._strWidth = function(str) {
-  if (!this.screen.fullUnicode) return str.length;
+  return this.screen.fullUnicode
-  str = str.replace(/\x03/g, '');
+    ? unicode.strWidth(str)
-  return unicode.strWidth(str, 0);
+    : str.length;
 };
 
 Textarea.prototype.input =