From dc27900b9af99b20ea87d8aacf6232c032d7b910 Mon Sep 17 00:00:00 2001
From: Olivier Couet <olivier.couet@gmail.com>
Date: Thu, 16 Jul 2026 11:10:13 +0200
Subject: [PATCH] Add a protection against undefined fPainter

---
 graf2d/gpad/src/TCanvas.cxx | 1 +
 1 file changed, 1 insertion(+)

diff --git a/graf2d/gpad/src/TCanvas.cxx b/graf2d/gpad/src/TCanvas.cxx
index ca66782ef96ce..0d1b3ec2f67e7 100644
--- a/graf2d/gpad/src/TCanvas.cxx
+++ b/graf2d/gpad/src/TCanvas.cxx
@@ -620,6 +620,7 @@ void TCanvas::Build()
    } else {
       //normal mode with a screen window
       // Set default physical canvas attributes
+      if (!fPainter) return;
       fPainter->SelectDrawable(fCanvasID);
       fPainter->SetAttFill({1, 1001});    //Set color index for fill area
       fPainter->SetAttLine({1, 1, 1});    //Set color index for lines