Preserve terminal feedback while coalescing repaints

internal/platform/wayland/routing_test.go

@@ -214,6 +214,25 @@ func TestBrowseShiftedDigitHeadingLevels(t *testing.T) {
 	}
 }
 
+func TestAmbiguousShiftPartnersAreNotGrabbed(t *testing.T) {
+	// US Shift+apostrophe and GB Shift+2 both produce a double quote.
+	// Without the active group, the monitor cannot route it reliably.
+	pairs := build_shift_pairs("us,gb")
+	if _, ok := pairs.unshifted['"']; ok {
+		t.Fatal("ambiguous double quote has a reverse mapping")
+	}
+	original := loadShiftPairs
+	loadShiftPairs = func() shiftPairs { return pairs }
+	t.Cleanup(func() { loadShiftPairs = original })
+	_, grabs, _ := make_grabs(keyboardConfiguration{layout: input.DesktopKeyboardLayout, modifiers: []string{"Insert"}},
+		keyboardPolicy{enabled: true, browse: true})
+	for _, grab := range grabs {
+		if grab.Symbol == '"' && grab.Modifiers&1 != 0 {
+			t.Fatalf("ambiguous shifted symbol grabbed: %+v", grab)
+		}
+	}
+}
+
 func TestLearnModeAndSecureReset(t *testing.T) {
 	owner := test_owner(t, input.LaptopKeyboardLayout, "Insert")
 	send_key(t, owner, 0xff63, 118, 0, false)