PdfWorker: generatePreviews: take const ref to container with search results

gui/pdfworker.cpp

@@ -74,11 +74,11 @@ struct Renderer
 
 
 
-QFuture<PdfPreview> PdfWorker::generatePreviews(QVector<SearchResult> paths, double scalefactor)
+QFuture<PdfPreview> PdfWorker::generatePreviews(const QVector<SearchResult> paths, double scalefactor)
 {
     QVector<PdfPreview> previews;
 
-    for(SearchResult &sr : paths)
+    for(const SearchResult &sr : paths)
     {
         for(int page : sr.pages)
         {

gui/pdfworker.h

@@ -17,7 +17,7 @@ class PdfWorker : public QObject
 {
     Q_OBJECT
 public:
-    QFuture<PdfPreview> generatePreviews(QVector<SearchResult> paths, double scalefactor);
+    QFuture<PdfPreview> generatePreviews(const QVector<SearchResult> paths, double scalefactor);
 };
 
 #endif // PDFWORKER_H