[LyX/master] With Qt6 on linux, we need to catch StyleChange here

[Juergen Spitzmueller]

commit 6bb72cc28c77b4f50464d0fe47d19c29ee5281b4
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Tue Sep 5 12:01:17 2023 +0200

    With Qt6 on linux, we need to catch StyleChange here
---
 src/frontends/qt/GuiViewSource.cpp |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/src/frontends/qt/GuiViewSource.cpp b/src/frontends/qt/GuiViewSource.cpp
index 2688d7f..5165c0e 100644
--- a/src/frontends/qt/GuiViewSource.cpp
+++ b/src/frontends/qt/GuiViewSource.cpp
@@ -320,7 +320,8 @@ bool ViewSourceWidget::eventFilter(QObject * obj, QEvent * ev)
 		goToCursor();
 		return true;
 	}
-	if (ev->type() == QEvent::ApplicationPaletteChange) {
+	if (ev->type() == QEvent::ApplicationPaletteChange
+	    || ev->type() == QEvent::StyleChange) {
 		// mode switch: colors need to be updated
 		// and the highlighting redone
 		if (highlighter_) {