Merge pull request #144 from jerch/wcwidth

wcwidth calculation

src/xterm.js

@@ -294,6 +294,9 @@
       this.prefix = '';
       this.postfix = '';
 
+      // leftover surrogate high from previous write invocation
+      this.surrogate_high = '';
+
       /**
        * An array of all lines in the entire buffer, including the prompt. The lines are array of
        * characters which are 2-length arrays where [0] is an attribute and [1] is the character.
@@ -1231,7 +1234,7 @@
         this._fullRefreshNext = false // reset lock
       }
 
-      var x, y, i, line, out, ch, width, data, attr, bg, fg, flags, row, parent, focused = document.activeElement;
+      var x, y, i, line, out, ch, ch_width, width, data, attr, bg, fg, flags, row, parent, focused = document.activeElement;
 
       // If this is a big refresh, remove the terminal rows from the DOM for faster calculations
       if (end - start >= this.rows / 2) {
@@ -1269,6 +1272,9 @@
         for (; i < width; i++) {
           data = line[i][0];
           ch = line[i][1];
+          ch_width = line[i][2];
+          if (!ch_width)
+            continue;
 
           if (i === x) data = -1;
 
@@ -1368,7 +1374,6 @@
               if (ch <= ' ') {
                 out += '&nbsp;';
               } else {
-                if (isWide(ch)) i++;
                 out += ch;
               }
               break;
@@ -1458,7 +1463,7 @@
      * @public
      */
     Terminal.prototype.write = function(data) {
-      var l = data.length, i = 0, j, cs, ch;
+      var l = data.length, i = 0, j, cs, ch, code, low, ch_width;
 
       this.refreshStart = this.y;
       this.refreshEnd = this.y;
@@ -1468,8 +1473,34 @@
         this.maxRange();
       }
 
+      // apply leftover surrogate high from last write
+      if (this.surrogate_high) {
+        data = this.surrogate_high + data;
+        this.surrogate_high = '';
+      }
+
       for (; i < l; i++) {
         ch = data[i];
+
+        // FIXME: higher chars than 0xa0 are not allowed in escape sequences
+        //        --> maybe move to default
+        code = data.charCodeAt(i);
+        if (0xD800 <= code && code <= 0xDBFF) {
+          // we got a surrogate high
+          // get surrogate low (next 2 bytes)
+          low = data.charCodeAt(i+1);
+          if (isNaN(low)) {
+            // end of data stream, save surrogate high
+            this.surrogate_high = ch;
+            continue;
+          }
+          code = ((code - 0xD800) * 0x400) + (low - 0xDC00) + 0x10000;
+          ch += data.charAt(i+1);
+        }
+        // surrogate low - already handled above
+        if (0xDC00 <= code && code <= 0xDFFF)
+          continue;
+
         switch (this.state) {
           case normal:
             switch (ch) {
@@ -1525,12 +1556,38 @@
 
               default:
                 // ' '
+                // calculate print space
+                // expensive call, therefore we save width in line buffer
+                ch_width = wcwidth(code);
+
                 if (ch >= ' ') {
                   if (this.charset && this.charset[ch]) {
                     ch = this.charset[ch];
                   }
 
-                  if (this.x >= this.cols) {
+                  // insert combining char in last cell
+                  // FIXME: needs handling after cursor jumps
+                  if (!ch_width && this.x) {
+                    
+                    // dont overflow left
+                    if (this.lines[this.y + this.ybase][this.x-1]) {
+                      if (!this.lines[this.y + this.ybase][this.x-1][2]) {
+
+                        // found empty cell after fullwidth, need to go 2 cells back
+                        if (this.lines[this.y + this.ybase][this.x-2])
+                          this.lines[this.y + this.ybase][this.x-2][1] += ch;
+
+                      } else {
+                        this.lines[this.y + this.ybase][this.x-1][1] += ch;
+                      }
+                      this.updateRange(this.y);
+                    }
+                    break;
+                  }
+
+                  // goto next line if ch would overflow
+                  // TODO: needs a global min terminal width of 2
+                  if (this.x+ch_width-1 >= this.cols) {
                     this.x = 0;
                     this.y++;
                     if (this.y > this.scrollBottom) {
@@ -1539,17 +1596,13 @@
                     }
                   }
 
-                  this.lines[this.y + this.ybase][this.x] = [this.curAttr, ch];
+                  this.lines[this.y + this.ybase][this.x] = [this.curAttr, ch, ch_width];
                   this.x++;
                   this.updateRange(this.y);
 
-                  if (isWide(ch)) {
-                    j = this.y + this.ybase;
-                    if (this.cols < 2 || this.x >= this.cols) {
-                      this.lines[j][this.x - 1] = [this.curAttr, ' '];
-                      break;
-                    }
-                    this.lines[j][this.x] = [this.curAttr, ' '];
+                  // fullwidth char - set next cell width to zero and advance cursor
+                  if (ch_width==2) {
+                    this.lines[this.y + this.ybase][this.x] = [this.curAttr, '', 0];
                     this.x++;
                   }
                 }
@@ -2908,7 +2961,7 @@
 
     Terminal.prototype.eraseRight = function(x, y) {
       var line = this.lines[this.ybase + y]
-        , ch = [this.eraseAttr(), ' ']; // xterm
+        , ch = [this.eraseAttr(), ' ', 1]; // xterm
 
 
       for (; x < this.cols; x++) {
@@ -2920,7 +2973,7 @@
 
     Terminal.prototype.eraseLeft = function(x, y) {
       var line = this.lines[this.ybase + y]
-        , ch = [this.eraseAttr(), ' ']; // xterm
+        , ch = [this.eraseAttr(), ' ', 1]; // xterm
 
       x++;
       while (x--) line[x] = ch;
@@ -2937,7 +2990,7 @@
         ? this.eraseAttr()
         : this.defAttr;
 
-      var ch = [attr, ' ']
+      var ch = [attr, ' ', 1]  // width defaults to 1 halfwidth character
         , line = []
         , i = 0;
 
@@ -2950,8 +3003,8 @@
 
     Terminal.prototype.ch = function(cur) {
       return cur
-        ? [this.eraseAttr(), ' ']
-        : [this.defAttr, ' '];
+        ? [this.eraseAttr(), ' ', 1]
+        : [this.defAttr, ' ', 1];
     };
 
     Terminal.prototype.is = function(term) {
@@ -4594,17 +4647,6 @@
       return thirdLevelKey && (!ev.keyCode || ev.keyCode > 47);
     }
 
-    function isWide(ch) {
-      if (ch <= '\uff00') return false;
-      return (ch >= '\uff01' && ch <= '\uffbe')
-          || (ch >= '\uffc2' && ch <= '\uffc7')
-          || (ch >= '\uffca' && ch <= '\uffcf')
-          || (ch >= '\uffd2' && ch <= '\uffd7')
-          || (ch >= '\uffda' && ch <= '\uffdc')
-          || (ch >= '\uffe0' && ch <= '\uffe6')
-          || (ch >= '\uffe8' && ch <= '\uffee');
-    }
-
     function matchColor(r1, g1, b1) {
       var hash = (r1 << 16) | (g1 << 8) | b1;
 
@@ -4670,6 +4712,109 @@
       return keys;
     }
 
+    var wcwidth = (function(opts) {
+      // extracted from https://www.cl.cam.ac.uk/%7Emgk25/ucs/wcwidth.c
+      // combining characters
+      var COMBINING = [
+        [0x0300, 0x036F], [0x0483, 0x0486], [0x0488, 0x0489],
+        [0x0591, 0x05BD], [0x05BF, 0x05BF], [0x05C1, 0x05C2],
+        [0x05C4, 0x05C5], [0x05C7, 0x05C7], [0x0600, 0x0603],
+        [0x0610, 0x0615], [0x064B, 0x065E], [0x0670, 0x0670],
+        [0x06D6, 0x06E4], [0x06E7, 0x06E8], [0x06EA, 0x06ED],
+        [0x070F, 0x070F], [0x0711, 0x0711], [0x0730, 0x074A],
+        [0x07A6, 0x07B0], [0x07EB, 0x07F3], [0x0901, 0x0902],
+        [0x093C, 0x093C], [0x0941, 0x0948], [0x094D, 0x094D],
+        [0x0951, 0x0954], [0x0962, 0x0963], [0x0981, 0x0981],
+        [0x09BC, 0x09BC], [0x09C1, 0x09C4], [0x09CD, 0x09CD],
+        [0x09E2, 0x09E3], [0x0A01, 0x0A02], [0x0A3C, 0x0A3C],
+        [0x0A41, 0x0A42], [0x0A47, 0x0A48], [0x0A4B, 0x0A4D],
+        [0x0A70, 0x0A71], [0x0A81, 0x0A82], [0x0ABC, 0x0ABC],
+        [0x0AC1, 0x0AC5], [0x0AC7, 0x0AC8], [0x0ACD, 0x0ACD],
+        [0x0AE2, 0x0AE3], [0x0B01, 0x0B01], [0x0B3C, 0x0B3C],
+        [0x0B3F, 0x0B3F], [0x0B41, 0x0B43], [0x0B4D, 0x0B4D],
+        [0x0B56, 0x0B56], [0x0B82, 0x0B82], [0x0BC0, 0x0BC0],
+        [0x0BCD, 0x0BCD], [0x0C3E, 0x0C40], [0x0C46, 0x0C48],
+        [0x0C4A, 0x0C4D], [0x0C55, 0x0C56], [0x0CBC, 0x0CBC],
+        [0x0CBF, 0x0CBF], [0x0CC6, 0x0CC6], [0x0CCC, 0x0CCD],
+        [0x0CE2, 0x0CE3], [0x0D41, 0x0D43], [0x0D4D, 0x0D4D],
+        [0x0DCA, 0x0DCA], [0x0DD2, 0x0DD4], [0x0DD6, 0x0DD6],
+        [0x0E31, 0x0E31], [0x0E34, 0x0E3A], [0x0E47, 0x0E4E],
+        [0x0EB1, 0x0EB1], [0x0EB4, 0x0EB9], [0x0EBB, 0x0EBC],
+        [0x0EC8, 0x0ECD], [0x0F18, 0x0F19], [0x0F35, 0x0F35],
+        [0x0F37, 0x0F37], [0x0F39, 0x0F39], [0x0F71, 0x0F7E],
+        [0x0F80, 0x0F84], [0x0F86, 0x0F87], [0x0F90, 0x0F97],
+        [0x0F99, 0x0FBC], [0x0FC6, 0x0FC6], [0x102D, 0x1030],
+        [0x1032, 0x1032], [0x1036, 0x1037], [0x1039, 0x1039],
+        [0x1058, 0x1059], [0x1160, 0x11FF], [0x135F, 0x135F],
+        [0x1712, 0x1714], [0x1732, 0x1734], [0x1752, 0x1753],
+        [0x1772, 0x1773], [0x17B4, 0x17B5], [0x17B7, 0x17BD],
+        [0x17C6, 0x17C6], [0x17C9, 0x17D3], [0x17DD, 0x17DD],
+        [0x180B, 0x180D], [0x18A9, 0x18A9], [0x1920, 0x1922],
+        [0x1927, 0x1928], [0x1932, 0x1932], [0x1939, 0x193B],
+        [0x1A17, 0x1A18], [0x1B00, 0x1B03], [0x1B34, 0x1B34],
+        [0x1B36, 0x1B3A], [0x1B3C, 0x1B3C], [0x1B42, 0x1B42],
+        [0x1B6B, 0x1B73], [0x1DC0, 0x1DCA], [0x1DFE, 0x1DFF],
+        [0x200B, 0x200F], [0x202A, 0x202E], [0x2060, 0x2063],
+        [0x206A, 0x206F], [0x20D0, 0x20EF], [0x302A, 0x302F],
+        [0x3099, 0x309A], [0xA806, 0xA806], [0xA80B, 0xA80B],
+        [0xA825, 0xA826], [0xFB1E, 0xFB1E], [0xFE00, 0xFE0F],
+        [0xFE20, 0xFE23], [0xFEFF, 0xFEFF], [0xFFF9, 0xFFFB],
+        [0x10A01, 0x10A03], [0x10A05, 0x10A06], [0x10A0C, 0x10A0F],
+        [0x10A38, 0x10A3A], [0x10A3F, 0x10A3F], [0x1D167, 0x1D169],
+        [0x1D173, 0x1D182], [0x1D185, 0x1D18B], [0x1D1AA, 0x1D1AD],
+        [0x1D242, 0x1D244], [0xE0001, 0xE0001], [0xE0020, 0xE007F],
+        [0xE0100, 0xE01EF]
+      ];
+      // binary search
+      function bisearch(ucs) {
+        var min = 0;
+        var max = COMBINING.length - 1;
+        var mid;
+        if (ucs < COMBINING[0][0] || ucs > COMBINING[max][1])
+          return false;
+        while (max >= min) {
+          mid = Math.floor((min + max) / 2);
+          if (ucs > COMBINING[mid][1])
+            min = mid + 1;
+          else if (ucs < COMBINING[mid][0])
+            max = mid - 1;
+          else
+            return true;
+        }
+        return false;
+      }
+      function wcwidth(ucs) {
+        // test for 8-bit control characters
+        if (ucs === 0)
+          return opts.nul;
+        if (ucs < 32 || (ucs >= 0x7f && ucs < 0xa0))
+          return opts.control;
+        // binary search in table of non-spacing characters
+        if (bisearch(ucs))
+          return 0;
+        // if we arrive here, ucs is not a combining or C0/C1 control character
+        return 1 +
+          (
+            ucs >= 0x1100 &&
+            (
+              ucs <= 0x115f ||                // Hangul Jamo init. consonants
+              ucs == 0x2329 ||
+              ucs == 0x232a ||
+              (ucs >= 0x2e80 && ucs <= 0xa4cf && ucs != 0x303f) ||  // CJK..Yi
+              (ucs >= 0xac00 && ucs <= 0xd7a3) ||    // Hangul Syllables
+              (ucs >= 0xf900 && ucs <= 0xfaff) ||    // CJK Compat Ideographs
+              (ucs >= 0xfe10 && ucs <= 0xfe19) ||    // Vertical forms
+              (ucs >= 0xfe30 && ucs <= 0xfe6f) ||    // CJK Compat Forms
+              (ucs >= 0xff00 && ucs <= 0xff60) ||    // Fullwidth Forms
+              (ucs >= 0xffe0 && ucs <= 0xffe6) ||
+              (ucs >= 0x20000 && ucs <= 0x2fffd) ||
+              (ucs >= 0x30000 && ucs <= 0x3fffd)
+            )
+          );
+      }
+      return wcwidth;
+    })({nul: 0, control: 0});  // configurable options
+
     /**
      * Expose
      */

test/test.js

@@ -1,4 +1,5 @@
 var assert = require('chai').assert;
+var chai = require('chai');
 var Terminal = require('../src/xterm');
 
 describe('xterm.js', function() {
@@ -190,4 +191,261 @@ describe('xterm.js', function() {
       });
     });
   });
+
+describe('unicode - surrogates', function() {
+    it('2 characters per cell', function () {
+        var high = '\uD800';
+        for (var i=0xDC00; i<=0xDCFF; ++i) {
+            xterm.write(high + String.fromCharCode(i));
+            var tchar = xterm.lines[0][0];
+            chai.expect(tchar[1]).eql(high + String.fromCharCode(i));
+            chai.expect(tchar[1].length).eql(2);
+            chai.expect(tchar[2]).eql(1);
+            chai.expect(xterm.lines[0][1][1]).eql(' ');
+            xterm.reset();
+        }
+    });
+    it('2 characters at last cell', function () {
+        var high = '\uD800';
+        for (var i=0xDC00; i<=0xDCFF; ++i) {
+            xterm.x = xterm.cols - 1;
+            xterm.write(high + String.fromCharCode(i));
+            chai.expect(xterm.lines[0][xterm.x-1][1]).eql(high + String.fromCharCode(i));
+            chai.expect(xterm.lines[0][xterm.x-1][1].length).eql(2);
+            chai.expect(xterm.lines[1][0][1]).eql(' ');
+            xterm.reset();
+        }
+    });
+    it('2 characters per cell over line end with autowrap', function () {
+        var high = '\uD800';
+        for (var i=0xDC00; i<=0xDCFF; ++i) {
+            xterm.x = xterm.cols - 1;
+            xterm.wraparoundMode = true;
+            xterm.write('a' + high + String.fromCharCode(i));
+            chai.expect(xterm.lines[0][xterm.cols-1][1]).eql('a');
+            chai.expect(xterm.lines[1][0][1]).eql(high + String.fromCharCode(i));
+            chai.expect(xterm.lines[1][0][1].length).eql(2);
+            chai.expect(xterm.lines[1][1][1]).eql(' ');
+            xterm.reset();
+        }
+    });
+    /** FIXME - wrap is not respected in default state */
+    /*
+    it('2 characters per cell over line end without autowrap', function () {
+        var high = '\uD800';
+        for (var i=0xDC00; i<=0xDCFF; ++i) {
+            xterm.x = xterm.cols - 1;
+            xterm.wraparoundMode = false;
+            xterm.write('a' + high + String.fromCharCode(i));
+            chai.expect(xterm.lines[0][xterm.cols-1][1]).eql(high + String.fromCharCode(i));
+            chai.expect(xterm.lines[0][xterm.cols-1][1].length).eql(2);
+            chai.expect(xterm.lines[1][1][1]).eql(' ');
+            xterm.reset();
+        }
+    });
+    */
+    it('splitted surrogates', function () {
+        var high = '\uD800';
+        for (var i=0xDC00; i<=0xDCFF; ++i) {
+            xterm.write(high);
+            xterm.write(String.fromCharCode(i));
+            var tchar = xterm.lines[0][0];
+            chai.expect(tchar[1]).eql(high + String.fromCharCode(i));
+            chai.expect(tchar[1].length).eql(2);
+            chai.expect(tchar[2]).eql(1);
+            chai.expect(xterm.lines[0][1][1]).eql(' ');
+            xterm.reset();
+        }
+    });
+});
+describe('unicode - combining characters', function() {
+    it('café', function () {
+        xterm.write('cafe\u0301');
+        chai.expect(xterm.lines[0][3][1]).eql('e\u0301');
+        chai.expect(xterm.lines[0][3][1].length).eql(2);
+        chai.expect(xterm.lines[0][3][2]).eql(1);
+    });
+    it('café - end of line', function () {
+        xterm.x = xterm.cols - 1 - 3;
+        xterm.write('cafe\u0301');
+        chai.expect(xterm.lines[0][xterm.cols-1][1]).eql('e\u0301');
+        chai.expect(xterm.lines[0][xterm.cols-1][1].length).eql(2);
+        chai.expect(xterm.lines[0][xterm.cols-1][2]).eql(1);
+        chai.expect(xterm.lines[0][1][1]).eql(' ');
+        chai.expect(xterm.lines[0][1][1].length).eql(1);
+        chai.expect(xterm.lines[0][1][2]).eql(1);
+    });
+    it('multiple combined é', function () {
+        xterm.write(Array(100).join('e\u0301'));
+        for (var i=0; i<xterm.cols; ++i) {
+            var tchar = xterm.lines[0][i];
+            chai.expect(tchar[1]).eql('e\u0301');
+            chai.expect(tchar[1].length).eql(2);
+            chai.expect(tchar[2]).eql(1);
+        }
+        tchar = xterm.lines[1][0];
+        chai.expect(tchar[1]).eql('e\u0301');
+        chai.expect(tchar[1].length).eql(2);
+        chai.expect(tchar[2]).eql(1);
+    });
+    it('multiple surrogate with combined', function () {
+        xterm.write(Array(100).join('\uD800\uDC00\u0301'));
+        for (var i=0; i<xterm.cols; ++i) {
+            var tchar = xterm.lines[0][i];
+            chai.expect(tchar[1]).eql('\uD800\uDC00\u0301');
+            chai.expect(tchar[1].length).eql(3);
+            chai.expect(tchar[2]).eql(1);
+        }
+        tchar = xterm.lines[1][0];
+        chai.expect(tchar[1]).eql('\uD800\uDC00\u0301');
+        chai.expect(tchar[1].length).eql(3);
+        chai.expect(tchar[2]).eql(1);
+    });
+});
+
+describe('unicode - fullwidth characters', function() {
+    it('cursor movement even', function () {
+        chai.expect(xterm.x).eql(0);
+        xterm.write('￥');
+        chai.expect(xterm.x).eql(2);
+    });
+    it('cursor movement odd', function () {
+        xterm.x = 1;
+        chai.expect(xterm.x).eql(1);
+        xterm.write('￥');
+        chai.expect(xterm.x).eql(3);
+    });
+    it('line of ￥ even', function () {
+        xterm.write(Array(50).join('￥'));
+        for (var i=0; i<xterm.cols; ++i) {
+            var tchar = xterm.lines[0][i];
+            if (i % 2) {
+                chai.expect(tchar[1]).eql('');
+                chai.expect(tchar[1].length).eql(0);
+                chai.expect(tchar[2]).eql(0);
+            } else {
+                chai.expect(tchar[1]).eql('￥');
+                chai.expect(tchar[1].length).eql(1);
+                chai.expect(tchar[2]).eql(2);
+            }
+        }
+        tchar = xterm.lines[1][0];
+        chai.expect(tchar[1]).eql('￥');
+        chai.expect(tchar[1].length).eql(1);
+        chai.expect(tchar[2]).eql(2);
+    });
+    it('line of ￥ odd', function () {
+        xterm.x = 1;
+        xterm.write(Array(50).join('￥'));
+        for (var i=1; i<xterm.cols-1; ++i) {
+            var tchar = xterm.lines[0][i];
+            if (!(i % 2)) {
+                chai.expect(tchar[1]).eql('');
+                chai.expect(tchar[1].length).eql(0);
+                chai.expect(tchar[2]).eql(0);
+            } else {
+                chai.expect(tchar[1]).eql('￥');
+                chai.expect(tchar[1].length).eql(1);
+                chai.expect(tchar[2]).eql(2);
+            }
+        }
+        tchar = xterm.lines[0][xterm.cols-1];
+        chai.expect(tchar[1]).eql(' ');
+        chai.expect(tchar[1].length).eql(1);
+        chai.expect(tchar[2]).eql(1);
+        tchar = xterm.lines[1][0];
+        chai.expect(tchar[1]).eql('￥');
+        chai.expect(tchar[1].length).eql(1);
+        chai.expect(tchar[2]).eql(2);
+    });
+    it('line of ￥ with combining odd', function () {
+        xterm.x = 1;
+        xterm.write(Array(50).join('￥\u0301'));
+        for (var i=1; i<xterm.cols-1; ++i) {
+            var tchar = xterm.lines[0][i];
+            if (!(i % 2)) {
+                chai.expect(tchar[1]).eql('');
+                chai.expect(tchar[1].length).eql(0);
+                chai.expect(tchar[2]).eql(0);
+            } else {
+                chai.expect(tchar[1]).eql('￥\u0301');
+                chai.expect(tchar[1].length).eql(2);
+                chai.expect(tchar[2]).eql(2);
+            }
+        }
+        tchar = xterm.lines[0][xterm.cols-1];
+        chai.expect(tchar[1]).eql(' ');
+        chai.expect(tchar[1].length).eql(1);
+        chai.expect(tchar[2]).eql(1);
+        tchar = xterm.lines[1][0];
+        chai.expect(tchar[1]).eql('￥\u0301');
+        chai.expect(tchar[1].length).eql(2);
+        chai.expect(tchar[2]).eql(2);
+    });
+    it('line of ￥ with combining even', function () {
+        xterm.write(Array(50).join('￥\u0301'));
+        for (var i=0; i<xterm.cols; ++i) {
+            var tchar = xterm.lines[0][i];
+            if (i % 2) {
+                chai.expect(tchar[1]).eql('');
+                chai.expect(tchar[1].length).eql(0);
+                chai.expect(tchar[2]).eql(0);
+            } else {
+                chai.expect(tchar[1]).eql('￥\u0301');
+                chai.expect(tchar[1].length).eql(2);
+                chai.expect(tchar[2]).eql(2);
+            }
+        }
+        tchar = xterm.lines[1][0];
+        chai.expect(tchar[1]).eql('￥\u0301');
+        chai.expect(tchar[1].length).eql(2);
+        chai.expect(tchar[2]).eql(2);
+    });
+    it('line of surrogate fullwidth with combining odd', function () {
+        xterm.x = 1;
+        xterm.write(Array(50).join('\ud843\ude6d\u0301'));
+        for (var i=1; i<xterm.cols-1; ++i) {
+            var tchar = xterm.lines[0][i];
+            if (!(i % 2)) {
+                chai.expect(tchar[1]).eql('');
+                chai.expect(tchar[1].length).eql(0);
+                chai.expect(tchar[2]).eql(0);
+            } else {
+                chai.expect(tchar[1]).eql('\ud843\ude6d\u0301');
+                chai.expect(tchar[1].length).eql(3);
+                chai.expect(tchar[2]).eql(2);
+            }
+        }
+        tchar = xterm.lines[0][xterm.cols-1];
+        chai.expect(tchar[1]).eql(' ');
+        chai.expect(tchar[1].length).eql(1);
+        chai.expect(tchar[2]).eql(1);
+        tchar = xterm.lines[1][0];
+        chai.expect(tchar[1]).eql('\ud843\ude6d\u0301');
+        chai.expect(tchar[1].length).eql(3);
+        chai.expect(tchar[2]).eql(2);
+    });
+    it('line of surrogate fullwidth with combining even', function () {
+        xterm.write(Array(50).join('\ud843\ude6d\u0301'));
+        for (var i=0; i<xterm.cols; ++i) {
+            var tchar = xterm.lines[0][i];
+            if (i % 2) {
+                chai.expect(tchar[1]).eql('');
+                chai.expect(tchar[1].length).eql(0);
+                chai.expect(tchar[2]).eql(0);
+            } else {
+                chai.expect(tchar[1]).eql('\ud843\ude6d\u0301');
+                chai.expect(tchar[1].length).eql(3);
+                chai.expect(tchar[2]).eql(2);
+            }
+        }
+        tchar = xterm.lines[1][0];
+        chai.expect(tchar[1]).eql('\ud843\ude6d\u0301');
+        chai.expect(tchar[1].length).eql(3);
+        chai.expect(tchar[2]).eql(2);
+    });
+});
+
+
+
 });