From 6810de85e12b4a590ffbe4a0e970116b37256ac7 Mon Sep 17 00:00:00 2001
From: Aleksandr Andrienko <aandrienko@codenvy.com>
Date: Sun, 25 Jun 2017 21:42:31 +0300
Subject: [PATCH] Fix turning from alt screen to normal screen and vice versa.
 Fix https://github.com/sourcelair/xterm.js/issues/229 .

---
 src/BufferSet.ts    | 12 ++----------
 src/InputHandler.ts | 25 +++++++++++++------------
 src/xterm.js        | 15 +++++++++------
 3 files changed, 24 insertions(+), 28 deletions(-)

diff --git a/src/BufferSet.ts b/src/BufferSet.ts
index 0429c52..c9022a9 100644
--- a/src/BufferSet.ts
+++ b/src/BufferSet.ts
@@ -30,21 +30,13 @@ export class BufferSet extends EventEmitter {
     return this._normal;
   }
 
-  private resetTerminal() {
-    this._terminal.reset();
-    this._terminal.viewport.syncScrollArea();
-    this._terminal.showCursor();
-  }
-
   public activateNormalBuffer(): void {
     this._activeBuffer = this._normal;
-    this.resetTerminal();
-    this.emit('activate', this._normal);
+    this.emit('activate', this._normal); // todo maybe simpler this._terminal.buffer = this._terminal.buffers.normal than using EventEmitter?
   }
 
   public activateAltBuffer(): void {
     this._activeBuffer = this._alt;
-    this.resetTerminal();
-    this.emit('activate', this._alt);
+    this.emit('activate', this._alt); // todo maybe simpler this._terminal.buffer = this._terminal.buffers.alt than using EventEmitter?
   }
 }
diff --git a/src/InputHandler.ts b/src/InputHandler.ts
index bf5b651..c9b5844 100644
--- a/src/InputHandler.ts
+++ b/src/InputHandler.ts
@@ -942,16 +942,14 @@ export class InputHandler implements IInputHandler {
           this._terminal.cursorHidden = false;
           break;
         case 1049: // alt screen buffer cursor
-          // this._terminal.saveCursor();
-          ; // FALL-THROUGH
+          this.saveCursor(params);
+          // FALL-THROUGH
         case 47: // alt screen buffer
         case 1047: // alt screen buffer
-          if (!this._terminal.normal) {
-            let normal = {
-              scrollBottom: this._terminal.buffer.scrollBottom,
-            };
-            this._terminal.buffers.activateAltBuffer();
-          }
+          this._terminal.buffers.activateAltBuffer();
+          this._terminal.reset();
+          this._terminal.viewport.syncScrollArea();
+          this._terminal.showCursor();
           break;
       }
     }
@@ -1114,6 +1112,9 @@ export class InputHandler implements IInputHandler {
         case 1047: // normal screen buffer - clearing it first
           // Ensure the selection manager has the correct buffer
           this._terminal.buffers.activateNormalBuffer();
+          if (params[0] === 1049) {
+            this.restoreCursor(params);
+          }
           this._terminal.selectionManager.setBuffer(this._terminal.buffer.lines);
           this._terminal.refresh(0, this._terminal.rows - 1);
           this._terminal.viewport.syncScrollArea();
@@ -1446,8 +1447,8 @@ export class InputHandler implements IInputHandler {
    *   Save cursor (ANSI.SYS).
    */
   public saveCursor(params: number[]): void {
-    this._terminal.savedX = this._terminal.buffer.x;
-    this._terminal.savedY = this._terminal.buffer.y;
+    this._terminal.buffers.active.x = this._terminal.buffer.x;
+    this._terminal.buffers.active.y = this._terminal.buffer.y;
   }
 
 
@@ -1456,8 +1457,8 @@ export class InputHandler implements IInputHandler {
    *   Restore cursor (ANSI.SYS).
    */
   public restoreCursor(params: number[]): void {
-    this._terminal.buffer.x = this._terminal.savedX || 0;
-    this._terminal.buffer.y = this._terminal.savedY || 0;
+    this._terminal.buffer.x = this._terminal.buffers.active.x || 0;
+    this._terminal.buffer.y = this._terminal.buffers.active.y || 0;
   }
 }
 
diff --git a/src/xterm.js b/src/xterm.js
index d1406cc..5fb5ea7 100644
--- a/src/xterm.js
+++ b/src/xterm.js
@@ -161,7 +161,6 @@ function Terminal(options) {
   this.originMode = false;
   this.insertMode = false;
   this.wraparoundMode = true; // defaults: xterm - true, vt100 - false
-  this.normal = null;
 
   // charset
   this.charset = null;
@@ -228,10 +227,12 @@ function Terminal(options) {
   this.surrogate_high = '';
 
   // Create the terminal's buffers and set the current buffer
-  this.buffers = new BufferSet(this);
-  this.buffer = this.buffers.active;  // Convenience shortcut;
+  if (!this.buffers) {
+    this.buffers = new BufferSet(this);
+    this.buffer = this.buffers.active;  // Convenience shortcut;
+  }
   this.buffers.on('activate', function (buffer) {
-    this.buffer = buffer;
+    this._terminal.buffer = buffer;
   });
 
   /**
@@ -2026,8 +2027,6 @@ Terminal.prototype.resize = function(x, y) {
 
   this.refresh(0, this.rows - 1);
 
-  this.normal = null;
-
   this.geometry = [this.cols, this.rows];
   this.emit('resize', {terminal: this, cols: x, rows: y});
 };
@@ -2305,9 +2304,13 @@ Terminal.prototype.reset = function() {
   this.options.cols = this.cols;
   var customKeyEventHandler = this.customKeyEventHandler;
   var cursorBlinkInterval = this.cursorBlinkInterval;
+  var inputHandler = this.inputHandler;
+  var buf = this.buffers;
   Terminal.call(this, this.options);
   this.customKeyEventHandler = customKeyEventHandler;
   this.cursorBlinkInterval = cursorBlinkInterval;
+  this.inputHandler = inputHandler;
+  this.buffers = buf;
   this.refresh(0, this.rows - 1);
   this.viewport.syncScrollArea();
 };
-- 
2.39.5