From 1a8f95043b8547496036ffced60153472b47f082 Mon Sep 17 00:00:00 2001
From: Jonathan Watt <jwatt@jwatt.org>
Date: Mon, 11 Dec 2023 18:00:36 +0000
Subject: [PATCH] Bug 1866383. Provide useful error reporting for page sizes
 mismatches in WPT Print Reftests. r=jgraham,webdriver-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D195999
---
 remote/marionette/reftest.sys.mjs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/remote/marionette/reftest.sys.mjs b/remote/marionette/reftest.sys.mjs
index baa3fb1b37bb..7c7a81f8ab27 100644
--- a/remote/marionette/reftest.sys.mjs
+++ b/remote/marionette/reftest.sys.mjs
@@ -529,6 +529,17 @@ reftest.Runner = class {
         lazy.logger.debug(
           `rhs canvas size ${rhs.canvas.width}x${rhs.canvas.height}`
         );
+        if (
+          lhs.canvas.width != rhs.canvas.width ||
+          lhs.canvas.height != rhs.canvas.height
+        ) {
+          msg =
+            `Got different page sizes; test is ` +
+            `${lhs.canvas.width}x${lhs.canvas.height}px, ref is ` +
+            `${rhs.canvas.width}x${rhs.canvas.height}px`;
+          passed = false;
+          break;
+        }
         try {
           pixelsDifferent = this.windowUtils.compareCanvases(
             lhs.canvas,