From 3624c478e6c3fee59b3bf04752b37359461319ec Mon Sep 17 00:00:00 2001
From: glacambre <code@lacamb.re>
Date: Fri, 19 Nov 2021 06:56:44 +0100
Subject: [PATCH] Fix negative-width/negative-space characters breaking the
 renderer

Closes #1243
---
 src/renderer.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/renderer.ts b/src/renderer.ts
index 28595e06..2b7ce0f2 100644
--- a/src/renderer.ts
+++ b/src/renderer.ts
@@ -953,7 +953,8 @@ function paint (_: DOMHighResTimeStamp) {
                             if (pixelX >= 0
                                 && pixelY >= 0
                                 && (pixelX + width < canvas.width)
-                                && (pixelY + charHeight < canvas.height)) {
+                                && (pixelY + charHeight < canvas.height)
+                                && width > 0 && charHeight > 0) {
                                 glyphCache[id] = context.getImageData(
                                     pixelX,
                                     pixelY,