The initial Slint problem was larger than thought. Hopefully a more universal fix.

internal/atspi/foreground.go

@@ -46,8 +46,10 @@ func foregroundWindowMatches(client xorg.Foreground, pid int, bounds Rectangle)
 	}
 	inner := Rectangle{X: int32(client.X), Y: int32(client.Y), Width: int32(client.Width), Height: int32(client.Height)}
 	outer := Rectangle{X: int32(client.OuterX), Y: int32(client.OuterY), Width: int32(client.OuterWidth), Height: int32(client.OuterHeight)}
+	frame := Rectangle{X: int32(client.FrameX), Y: int32(client.FrameY), Width: int32(client.FrameWidth), Height: int32(client.FrameHeight)}
 	return bounds == inner || bounds == outer ||
-		scaledWindowMatches(bounds, inner) || scaledWindowMatches(bounds, outer)
+		frame.Valid() && bounds == frame ||
+		scaledWindowMatches(bounds, inner) || scaledWindowMatches(bounds, outer) || scaledWindowMatches(bounds, frame)
 }
 
 // Some Chromium windows report AT-SPI extents in logical pixels while X11

internal/atspi/foreground_test.go

@@ -44,6 +44,33 @@ func TestForegroundWindowCorrelationSteamBigPictureScale(t *testing.T) {
 	}
 }
 
+func TestForegroundReparentedFrameCorrelation(t *testing.T) {
+	client := xorg.Foreground{Known: true, Window: 45, PID: 123,
+		X: 2, Y: 18, Width: 1912, Height: 974, OuterX: 2, OuterY: 18, OuterWidth: 1912, OuterHeight: 974,
+		FrameX: 0, FrameY: 0, FrameWidth: 1916, FrameHeight: 994}
+	for _, test := range []struct {
+		name   string
+		pid    int
+		bounds Rectangle
+		want   bool
+	}{
+		{"actual WM frame", 123, Rectangle{0, 0, 1916, 994}, true},
+		{"client still accepted", 123, Rectangle{2, 18, 1912, 974}, true},
+		{"other process same frame size", 124, Rectangle{0, 0, 1916, 994}, false},
+		{"same process other frame", 123, Rectangle{1920, 0, 1916, 994}, false},
+		{"same process smaller dialog", 123, Rectangle{20, 30, 400, 300}, false},
+		{"scaled frame same origin", 123, Rectangle{0, 0, 958, 497}, true},
+		{"scaled frame wrong origin", 123, Rectangle{1, 0, 958, 497}, false},
+		{"scaled frame wrong aspect", 123, Rectangle{0, 0, 958, 400}, false},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			if got := foregroundWindowMatches(client, test.pid, test.bounds); got != test.want {
+				t.Fatalf("match = %v, want %v", got, test.want)
+			}
+		})
+	}
+}
+
 func TestPreferencesForegroundIdentity(t *testing.T) {
 	// Slint/i3 reports GTK's frame and the X11 client with different borders.
 	client := xorg.Foreground{Known: true, Window: 45, PID: 123,