From e40cf0684eba2314af92467768b6546255760438 Mon Sep 17 00:00:00 2001
From: Daniel Imms <2193314+Tyriar@users.noreply.github.com>
Date: Wed, 24 Aug 2022 15:36:03 -0700
Subject: [PATCH] Properly clear underscore glyph's background

See microsoft/vscode#158497
---
 addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts b/addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts
index 13dceae67c..33b514b9ab 100644
--- a/addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts
+++ b/addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts
@@ -560,7 +560,10 @@ export class WebglCharAtlas implements IDisposable {
       let isBeyondCellBounds = clearColor(this._tmpCtx.getImageData(padding, padding, this._config.scaledCellWidth, this._config.scaledCellHeight), backgroundColor, foregroundColor, enableClearThresholdCheck);
       if (isBeyondCellBounds) {
         for (let offset = 1; offset <= 5; offset++) {
-          this._tmpCtx.clearRect(0, 0, this._tmpCanvas.width, this._tmpCanvas.height);
+          this._tmpCtx.save();
+          this._tmpCtx.fillStyle = backgroundColor.css;
+          this._tmpCtx.fillRect(0, 0, this._tmpCanvas.width, this._tmpCanvas.height);
+          this._tmpCtx.restore();
           this._tmpCtx.fillText(chars, padding, padding + this._config.scaledCharHeight - offset);
           isBeyondCellBounds = clearColor(this._tmpCtx.getImageData(padding, padding, this._config.scaledCellWidth, this._config.scaledCellHeight), backgroundColor, foregroundColor, enableClearThresholdCheck);
           if (!isBeyondCellBounds) {