Merge pull request #749 from irokas/fix-scrollback

Fix issue with small scrollback value

src/test/test.js

@@ -55,6 +55,11 @@ describe('xterm.js', function() {
     it('should throw when setting a non-existant option', function() {
       assert.throws(xterm.setOption.bind(xterm, 'fake', true));
     });
+    it('should not allow scrollback less than number of rows', function() {
+      let setOptionCall = xterm.setOption.bind(xterm, 'scrollback', xterm.rows - 1);
+
+      assert.equal(setOptionCall(), false);
+    });
   });
 
   describe('clear', function() {

src/xterm.js

@@ -419,6 +419,15 @@ Terminal.prototype.setOption = function(key, value) {
   }
   switch (key) {
     case 'scrollback':
+      if (value < this.rows) {
+        let msg = 'Setting the scrollback value less than the number of rows ';
+
+        msg += `(${this.rows}) is not allowed.`;
+
+        console.warn(msg);
+        return false;
+      }
+
       if (this.options[key] !== value) {
         if (this.lines.length > value) {
           const amountToTrim = this.lines.length - value;