Don't try to read first item in DbAnalyzerDialog when list is empty

Don't crash when data is empty in DbAnalyzerDialog::populate or the last
item was deleted.

1 files changed, 3 insertions, 0 deletions

diff --git a/dbanalyzer.cpp b/dbanalyzer.cpp
index d121f6b..7243e68 100644
--- a/dbanalyzer.cpp
+++ b/dbanalyzer.cpp
@@ -284,6 +284,9 @@ void DbAnalyzerDialog::deleteMarks(){
 }
 
 void DbAnalyzerDialog::populate(QTreeView *view, SmTreeModel *model, const QList<QList<QVariant> > &data, const QHash<int, QVariant> &marks){
+    if(data.isEmpty()){
+        return;
+    }
     const int columns = data.first().count();
     if(columns == 0){
         return;