surrogate. one flew over the 杜鹃's nest.

lib/widget.js

@@ -5879,8 +5879,7 @@ Textarea.prototype._listener = function(ch, key) {
   } else if (key.name === 'backspace') {
     if (this.value.length) {
       if (this.screen.fullUnicode) {
-        if (this.value[this.value.length - 2]
-            && unicode.isSurrogate(this.value[this.value.length - 2])) {
+        if (unicode.isSurrogate(this.value, this.value.length - 2)) {
           this.value = this.value.slice(0, -2);
         } else {
           this.value = this.value.slice(0, -1);

test/widget-eaw.js

@@ -16,13 +16,20 @@ screen = blessed.screen({
 // screen.tput.numbers.U8 = -1;
 // screen.tput.strings.enter_alt_charset_mode = false;
 
-// var DOUBLE = '杜';
-// '杜'
-var DOUBLE = String.fromCodePoint
-  ? String.fromCodePoint(0x675c)
-  : String.fromCharCode(0x675c);
+// du juan (dou gyun?)
+var DU = '杜';
+var JUAN = '鹃';
+
+// var DU = String.fromCodePoint
+//   ? String.fromCodePoint(0x675c)
+//   : String.fromCharCode(0x675c);
+
+// var DOUBLE = DU;
 // var DOUBLE = String.fromCodePoint(0x1F250);
 
+// one flew over the 杜鹃's nest.
+var DOUBLE = DU + JUAN;
+
 // var SURROGATE_DOUBLE = '𰀀';
 var SURROGATE_DOUBLE = String.fromCodePoint
   ? String.fromCodePoint(0x30000)
@@ -89,6 +96,8 @@ var lorem = 'Non eram nes' + (!~process.argv.indexOf('s') ? COMBINE : '')
 + ' legantur';
 
 lorem = lorem.replace(/e/gi, DOUBLE);
+//lorem = lorem.replace(/e/gi, DU);
+//lorem = lorem.replace(/r/gi, JUAN);
 // NOTE: libvte breaks when trying to display
 // this surrogate pair double width character:
 if (~process.argv.indexOf('vte')) {