fix(xterm-addon-webgl): wide characters overflow the cache canvas

addons/xterm-addon-webgl/src/atlas/WebglCharAtlas.ts

@@ -14,8 +14,9 @@ import { AttributeData } from 'common/buffer/AttributeData';
 import { channels, rgba } from 'browser/Color';
 import { tryDrawCustomChar } from 'browser/renderer/CustomGlyphs';
 
-// In practice we're probably never going to exhaust a texture this large. For debugging purposes,
-// however, it can be useful to set this to a really tiny value, to verify that LRU eviction works.
+// FIXME: rendering many characters can overflow the texture rarely
+// For debugging purposes, it can be useful to set this to a really tiny value,
+// to verify that LRU eviction works.
 const TEXTURE_WIDTH = 1024;
 const TEXTURE_HEIGHT = 1024;
 
@@ -463,7 +464,7 @@ export class WebglCharAtlas implements IDisposable {
     const clippedImageData = this._clipImageData(imageData, this._workBoundingBox);
 
     // Check if there is enough room in the current row and go to next if needed
-    if (this._currentRowX + this._config.scaledCharWidth > TEXTURE_WIDTH) {
+    if (this._currentRowX + rasterizedGlyph.size.x > TEXTURE_WIDTH) {
       this._currentRowX = 0;
       this._currentRowY += this._currentRowHeight;
       this._currentRowHeight = 0;