From b39d24505010c99977e257ba9f3a0c780145b6dd Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Thu, 3 Feb 2022 08:32:24 -0800
Subject: [PATCH 1/2] Log parsing data string when using buffers

---
 src/common/InputHandler.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/common/InputHandler.ts b/src/common/InputHandler.ts
index 68660f88..88634048 100644
--- a/src/common/InputHandler.ts
+++ b/src/common/InputHandler.ts
@@ -546,7 +546,7 @@ export class InputHandler extends Disposable implements IInputHandler {
 
     // Log debug data, the log level gate is to prevent extra work in this hot path
     if (this._logService.logLevel <= LogLevelEnum.DEBUG) {
-      this._logService.debug(`parsing data${typeof data === 'string' ? ` "${data}"` : ''}`, typeof data === 'string'
+      this._logService.debug(`parsing data${typeof data === 'string' ? ` "${data}"` : ` "${Array.prototype.map.call(data, e => String.fromCharCode(e)).join('')}"`}`, typeof data === 'string'
         ? data.split('').map(e => e.charCodeAt(0))
         : data
       );

From fea1079b1ec91b2406ea73a3cbda0e940436bf73 Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Thu, 3 Feb 2022 08:33:22 -0800
Subject: [PATCH 2/2] Force clear of the glyph renderer when switching

Fixes #3617
---
 addons/xterm-addon-webgl/src/GlyphRenderer.ts | 43 +++++++++++--------
 addons/xterm-addon-webgl/src/WebglRenderer.ts |  2 +
 src/browser/services/RenderService.ts         |  3 +-
 3 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/addons/xterm-addon-webgl/src/GlyphRenderer.ts b/addons/xterm-addon-webgl/src/GlyphRenderer.ts
index 71b3659e..e2c37be2 100644
--- a/addons/xterm-addon-webgl/src/GlyphRenderer.ts
+++ b/addons/xterm-addon-webgl/src/GlyphRenderer.ts
@@ -299,32 +299,37 @@ export class GlyphRenderer {
     return this._colors.ansi[idx];
   }
 
-  public onResize(): void {
+  public clear(force?: boolean): void {
     const terminal = this._terminal;
-    const gl = this._gl;
-
-    gl.viewport(0, 0, gl.canvas.width, gl.canvas.height);
-
-    // Update vertices
     const newCount = terminal.cols * terminal.rows * INDICES_PER_CELL;
-    if (this._vertices.count !== newCount) {
-      this._vertices.count = newCount;
-      this._vertices.attributes = new Float32Array(newCount);
-      for (let i = 0; i < this._vertices.attributesBuffers.length; i++) {
-        this._vertices.attributesBuffers[i] = new Float32Array(newCount);
-      }
 
-      let i = 0;
-      for (let y = 0; y < terminal.rows; y++) {
-        for (let x = 0; x < terminal.cols; x++) {
-          this._vertices.attributes[i + 8] = x / terminal.cols;
-          this._vertices.attributes[i + 9] = y / terminal.rows;
-          i += INDICES_PER_CELL;
-        }
+    // Don't clear if not forced and the array length is correct
+    if (!force && this._vertices.count === newCount) {
+      return;
+    }
+
+    // Clear vertices
+    this._vertices.count = newCount;
+    this._vertices.attributes = new Float32Array(newCount);
+    for (let i = 0; i < this._vertices.attributesBuffers.length; i++) {
+      this._vertices.attributesBuffers[i] = new Float32Array(newCount);
+    }
+    let i = 0;
+    for (let y = 0; y < terminal.rows; y++) {
+      for (let x = 0; x < terminal.cols; x++) {
+        this._vertices.attributes[i + 8] = x / terminal.cols;
+        this._vertices.attributes[i + 9] = y / terminal.rows;
+        i += INDICES_PER_CELL;
       }
     }
   }
 
+  public onResize(): void {
+    const gl = this._gl;
+    gl.viewport(0, 0, gl.canvas.width, gl.canvas.height);
+    this.clear();
+  }
+
   public setColors(): void {
   }
 
diff --git a/addons/xterm-addon-webgl/src/WebglRenderer.ts b/addons/xterm-addon-webgl/src/WebglRenderer.ts
index af1591a8..24e55fed 100644
--- a/addons/xterm-addon-webgl/src/WebglRenderer.ts
+++ b/addons/xterm-addon-webgl/src/WebglRenderer.ts
@@ -247,6 +247,8 @@ export class WebglRenderer extends Disposable implements IRenderer {
   }
 
   public clear(): void {
+    this._model.clear();
+    this._glyphRenderer.clear(true);
     for (const l of this._renderLayers) {
       l.reset(this._terminal);
     }
diff --git a/src/browser/services/RenderService.ts b/src/browser/services/RenderService.ts
index b8283e0e..da458abc 100644
--- a/src/browser/services/RenderService.ts
+++ b/src/browser/services/RenderService.ts
@@ -65,7 +65,8 @@ export class RenderService extends Disposable implements IRenderService {
     this._screenDprMonitor.setListener(() => this.onDevicePixelRatioChange());
     this.register(this._screenDprMonitor);
 
-    this.register(bufferService.onResize(e => this._fullRefresh()));
+    this.register(bufferService.onResize(() => this._fullRefresh()));
+    this.register(bufferService.buffers.onBufferActivate(() => this._renderer?.clear()));
     this.register(optionsService.onOptionChange(() => this._renderer.onOptionsChanged()));
     this.register(this._charSizeService.onCharSizeChange(() => this.onCharSizeChanged()));