[LyX/master] Do not attempt to show module info for category headers

[Juergen Spitzmueller]

commit dfde45a01a6cf1c74c4608c7126c9e8bb057ff96
Author: Juergen Spitzmueller <sp...@lyx.org>
Date:   Sun Apr 7 13:57:41 2019 +0200

    Do not attempt to show module info for category headers
---
 src/frontends/qt4/GuiDocument.cpp |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/src/frontends/qt4/GuiDocument.cpp 
b/src/frontends/qt4/GuiDocument.cpp
index cf8d999..26ffc95 100644
--- a/src/frontends/qt4/GuiDocument.cpp
+++ b/src/frontends/qt4/GuiDocument.cpp
@@ -2972,6 +2972,14 @@ void GuiDocument::updateModuleInfo()
                return;
        }
        QModelIndex const & idx = lv->selectionModel()->currentIndex();
+
+       if (!focus_on_selected
+           && modules_av_model_.itemFromIndex(idx)->hasChildren()) {
+               // This is a category header
+               modulesModule->infoML->document()->clear();
+               return;
+       }
+
        string const modName = focus_on_selected ?
                                modules_sel_model_.getIDString(idx.row())
                              : fromqstr(modules_av_model_.data(idx, 
Qt::UserRole).toString());