From 0a98cce8de9a8df20021eb9fe020886c49ff22ea Mon Sep 17 00:00:00 2001
From: Andre Rummler <andre.rummler@cern.ch>
Date: Fri, 28 Aug 2026 19:55:29 +0200
Subject: [PATCH] Fix: avoid crash when opening a project without a folio
 (diagram).

---
 sources/projectview.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sources/projectview.cpp b/sources/projectview.cpp
index b1bcc5077..768fb816b 100644
--- a/sources/projectview.cpp
+++ b/sources/projectview.cpp
@@ -210,10 +210,14 @@ void ProjectView::changeFirstTab()
 }
 
 /**
-	@return first folio of current project
+	@return first folio of current project, or nullptr if the project
+	has no diagram.
 */
 DiagramView *ProjectView::firstDiagram()
 {
+	if (m_diagram_ids.isEmpty()) {
+		return(nullptr);
+	}
 	return(m_diagram_ids.first());
 }