Merge pull request #4508 from Tyriar/4507_zalgo

Disallow glyphs to exceed atlas texture size

Author: Tyriar

src/browser/renderer/shared/TextureAtlas.ts

@@ -429,12 +429,12 @@ export class TextureAtlas implements ITextureAtlas {
     // Allow 1 cell width per character, with a minimum of 2 (CJK), plus some padding. This is used
     // to draw the glyph to the canvas as well as to restrict the bounding box search to ensure
     // giant ligatures (eg. =====>) don't impact overall performance.
-    const allowedWidth = this._config.deviceCellWidth * Math.max(chars.length, 2) + TMP_CANVAS_GLYPH_PADDING * 2;
+    const allowedWidth = Math.min(this._config.deviceCellWidth * Math.max(chars.length, 2) + TMP_CANVAS_GLYPH_PADDING * 2, this._textureSize);
     if (this._tmpCanvas.width < allowedWidth) {
       this._tmpCanvas.width = allowedWidth;
     }
     // Include line height when drawing glyphs
-    const allowedHeight = this._config.deviceCellHeight + TMP_CANVAS_GLYPH_PADDING * 4;
+    const allowedHeight = Math.min(this._config.deviceCellHeight + TMP_CANVAS_GLYPH_PADDING * 4, this._textureSize);
     if (this._tmpCanvas.height < allowedHeight) {
       this._tmpCanvas.height = allowedHeight;
     }