From 4b8a5349206e97e9040ad2ff4af8d62ca992d719 Mon Sep 17 00:00:00 2001
From: Snider <snider@host.uk.com>
Date: Fri, 17 Apr 2026 18:44:19 +0100
Subject: [PATCH] Harden screen query failure handling

---
 pkg/display/api.go      |  5 ++++-
 pkg/display/api_test.go | 22 ++++++++++++++++++++--
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/pkg/display/api.go b/pkg/display/api.go
index ce01a907..5f91ad77 100644
--- a/pkg/display/api.go
+++ b/pkg/display/api.go
@@ -90,10 +90,13 @@ func failedQuery(method, query string) error {
 func (s *Service) GetScreens() []*Screen {
 	r := s.Core().QUERY(screen.QueryAll{})
 	if !r.OK {
-		return nil
+		return []*Screen{}
 	}
 	screens, ok := r.Value.([]screen.Screen)
 	if !ok {
+		return []*Screen{}
+	}
+	if len(screens) == 0 {
 		return nil
 	}
 	result := make([]*Screen, 0, len(screens))
diff --git a/pkg/display/api_test.go b/pkg/display/api_test.go
index 37ad023e..dca0c5c0 100644
--- a/pkg/display/api_test.go
+++ b/pkg/display/api_test.go
@@ -153,6 +153,20 @@ func TestDisplayAPI_GetScreens_Good(t *testing.T) {
 	assert.Equal(t, 1920, screens[0].Width)
 }
 
+func TestDisplayAPI_GetScreens_Empty(t *testing.T) {
+	svc, c := newTestDisplayAPIService(t)
+	c.RegisterQuery(func(_ *core.Core, q core.Query) core.Result {
+		switch q.(type) {
+		case screen.QueryAll:
+			return core.Result{Value: []screen.Screen{}, OK: true}
+		default:
+			return core.Result{}
+		}
+	})
+
+	assert.Nil(t, svc.GetScreens())
+}
+
 func TestDisplayAPI_GetScreens_Bad(t *testing.T) {
 	svc, c := newTestDisplayAPIService(t)
 	c.RegisterQuery(func(_ *core.Core, q core.Query) core.Result {
@@ -164,7 +178,9 @@ func TestDisplayAPI_GetScreens_Bad(t *testing.T) {
 		}
 	})
 
-	assert.Nil(t, svc.GetScreens())
+	screens := svc.GetScreens()
+	require.NotNil(t, screens)
+	assert.Empty(t, screens)
 }
 
 func TestDisplayAPI_GetScreens_Ugly(t *testing.T) {
@@ -178,7 +194,9 @@ func TestDisplayAPI_GetScreens_Ugly(t *testing.T) {
 		}
 	})
 
-	assert.Nil(t, svc.GetScreens())
+	screens := svc.GetScreens()
+	require.NotNil(t, screens)
+	assert.Empty(t, screens)
 }
 
 func TestDisplayAPI_GetScreen_BadType(t *testing.T) {