[LyX/master] Check for invalid indexes in Module selection

[Juergen Spitzmueller]

commit c227a4af41771771f87fd073ebaba2572d668ab3
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Wed Mar 8 08:24:38 2023 +0100

    Check for invalid indexes in Module selection
    
    This should fix crashes when moving with pressed mouse buttons on
    category nods
---
 src/frontends/qt/GuiDocument.cpp |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/src/frontends/qt/GuiDocument.cpp b/src/frontends/qt/GuiDocument.cpp
index 8af5606..3a8ae85 100644
--- a/src/frontends/qt/GuiDocument.cpp
+++ b/src/frontends/qt/GuiDocument.cpp
@@ -324,6 +324,9 @@ void ModuleSelectionManager::updateAddPB()
 	}
 
 	QModelIndex const & idx = availableLV->selectionModel()->currentIndex();
+	
+	if (!idx.isValid())
+		return;
 
 	if (getAvailableModel()->itemFromIndex(idx)->hasChildren()) {
 		// This is a category header
@@ -3337,6 +3340,9 @@ void GuiDocument::updateModuleInfo()
 	}
 	QModelIndex const & idx = lv->selectionModel()->currentIndex();
 
+	if (!idx.isValid())
+		return;
+
 	if (!focus_on_selected
 	    && modules_av_model_.itemFromIndex(idx)->hasChildren()) {
 		// This is a category header