Warnings (#406)

* Fixes compiler warnings about unused variable/parameters

* Fix Clang warning about unused this lambda capture

In this case the this pointer is implicitly captured and Clang issues a
warning.

src/core/filechangeattrjob.cpp

@@ -152,7 +152,7 @@ bool FileChangeAttrJob::processFile(const FilePath& path, const GFileInfoPtr& in
     return ret;
 }
 
-bool FileChangeAttrJob::handleError(GErrorPtr &err, const FilePath &path, const GFileInfoPtr &info, ErrorSeverity severity) {
+bool FileChangeAttrJob::handleError(GErrorPtr &err, const FilePath & /*path*/, const GFileInfoPtr & /*info*/, ErrorSeverity severity) {
     auto act = emitError(err, severity);
     if (act == ErrorAction::RETRY) {
         err.reset();

src/core/filetransferjob.cpp

@@ -145,7 +145,7 @@ bool FileTransferJob::copySpecialFile(const FilePath& srcPath, const GFileInfoPt
     return ret;
 }
 
-bool FileTransferJob::copyDirContent(const FilePath& srcPath, GFileInfoPtr srcInfo, FilePath& destPath, bool skip) {
+bool FileTransferJob::copyDirContent(const FilePath& srcPath, GFileInfoPtr /*srcInfo*/, FilePath& destPath, bool skip) {
     bool ret = false;
     // copy dir content
     GErrorPtr err;

src/folderview.cpp

@@ -372,7 +372,7 @@ void FolderViewTreeView::headerContextMenu(const QPoint &p) {
                 }
                 else {
                     action->setChecked(!header()->isSectionHidden(columnId));
-                    connect(action, &QAction::triggered, action, [this, column, columnId] (bool checked) {
+                    connect(action, &QAction::triggered, action, [this, column] (bool checked) {
                         if(checked) {
                             hiddenColumns_.remove(column);
                         }
@@ -424,7 +424,6 @@ void FolderViewTreeView::mousePressEvent(QMouseEvent* event) {
     mousePressPoint_ = event->pos() + QPoint(horizontalOffset(), verticalOffset());
     QModelIndex index = indexAt(event->pos());
     if(index.isValid()) {
-        QItemSelectionModel::SelectionFlags command;
         Qt::KeyboardModifiers modifiers = QApplication::keyboardModifiers();
         const Qt::MouseButton button = static_cast<const QMouseEvent*>(event)->button();
         const bool shiftKeyPressed = modifiers & Qt::ShiftModifier;

src/placesview.cpp

@@ -157,7 +157,7 @@ PlacesView::PlacesView(QWidget* parent):
         // for some reason (a Qt bug?), spanning is reset
         spanFirstColumn();
     });
-    connect(model_.get(), &QAbstractItemModel::rowsRemoved, this, [this](const QModelIndex&, int, int) {
+    connect(model_.get(), &QAbstractItemModel::rowsRemoved, this, [](const QModelIndex&, int, int) {
         proxyModel_->setHidden(QString());
     });