Fix many MSVC compiler warnings.

src/Menus.cpp

@@ -220,9 +220,9 @@ void VisitItem( AudacityProject &project, MenuTable::BaseItem *pItem )
    else
    if (const auto pSpecial =
        dynamic_cast<SpecialItem*>( pItem )) {
-      const auto pMenu = manager.CurrentMenu();
-      wxASSERT( pMenu );
-      pSpecial->fn( project, *pMenu );
+      const auto pCurrentMenu = manager.CurrentMenu();
+      wxASSERT( pCurrentMenu );
+      pSpecial->fn( project, *pCurrentMenu );
    }
    else
       wxASSERT( false );

src/MixerBoard.h

@@ -25,7 +25,7 @@
 #include "widgets/ASlider.h"
 #include "widgets/wxPanelWrapper.h"
 
-class TrackListEvent;
+struct TrackListEvent;
 
 // containment hierarchy:
 //    MixerBoardFrame -> MixerBoard -> MixerBoardScrolledWindow -> MixerTrackCluster(s)

src/SelectionState.cpp

@@ -36,7 +36,7 @@ void SelectionState::SelectTrackLength
 void SelectionState::SelectTrack(
    Track &track, bool selected, bool updateLastPicked )
 {
-   bool wasCorrect = (selected == track.GetSelected());
+   //bool wasCorrect = (selected == track.GetSelected());
 
    for (auto channel : TrackList::Channels(&track))
       channel->SetSelected(selected);

src/TrackPanel.h

@@ -33,7 +33,7 @@ class LabelTrack;
 class SpectrumAnalyst;
 class Track;
 class TrackList;
-class TrackListEvent;
+struct TrackListEvent;
 class TrackPanel;
 class TrackArtist;
 class Ruler;

src/commands/CommandManager.h

@@ -570,7 +570,8 @@ namespace MenuTable {
             std::forward<Args>(args)... ); }
    inline BaseItemPtr Items(
       const wxString &title, BaseItemPtrs &&items )
-         { return std::make_unique<GroupItem>( std::move( items ) ); }
+         { (void)title; // Compiler food
+            return std::make_unique<GroupItem>( std::move( items ) ); }
 
    // Menu items can be constructed two ways, as for group items
    // Items will appear in a main toolbar menu or in a sub-menu

src/menus/EditMenus.cpp

@@ -218,7 +218,7 @@ void DoUndo(AudacityProject &project)
 {
    auto trackPanel = project.GetTrackPanel();
    auto &undoManager = *project.GetUndoManager();
-   auto historyWindow = project.GetHistoryWindow();
+   //auto historyWindow = project.GetHistoryWindow();
 
    if (!project.UndoAvailable()) {
       AudacityMessageBox(_("Nothing to undo"));
@@ -254,7 +254,7 @@ void OnRedo(const CommandContext &context)
    auto &project = context.project;
    auto trackPanel = project.GetTrackPanel();
    auto &undoManager = *project.GetUndoManager();
-   auto historyWindow = project.GetHistoryWindow();
+   //auto historyWindow = project.GetHistoryWindow();
 
    if (!project.RedoAvailable()) {
       AudacityMessageBox(_("Nothing to redo"));
@@ -282,7 +282,7 @@ void OnCut(const CommandContext &context)
    auto trackPanel = project.GetTrackPanel();
    auto &selectedRegion = project.GetViewInfo().selectedRegion;
    auto ruler = project.GetRulerPanel();
-   auto historyWindow = project.GetHistoryWindow();
+   //auto historyWindow = project.GetHistoryWindow();
 
    // This doesn't handle cutting labels, it handles
    // cutting the _text_ inside of labels, i.e. if you're
@@ -392,7 +392,7 @@ void OnCopy(const CommandContext &context)
    auto tracks = project.GetTracks();
    auto trackPanel = project.GetTrackPanel();
    auto &selectedRegion = project.GetViewInfo().selectedRegion;
-   auto historyWindow = project.GetHistoryWindow();
+   //auto historyWindow = project.GetHistoryWindow();
 
    for (auto lt : tracks->Selected< LabelTrack >()) {
       if (lt->CopySelectedText()) {
@@ -723,7 +723,7 @@ void OnSplitCut(const CommandContext &context)
    auto &project = context.project;
    auto tracks = project.GetTracks();
    auto &selectedRegion = project.GetViewInfo().selectedRegion;
-   auto historyWindow = project.GetHistoryWindow();
+   //auto historyWindow = project.GetHistoryWindow();
 
    AudacityProject::ClearClipboard();
 
@@ -1080,6 +1080,7 @@ MenuTable::BaseItemPtr LabelEditMenus( AudacityProject &project );
 
 MenuTable::BaseItemPtr EditMenu( AudacityProject &project )
 {
+   (void)project;// Compiler food
    using namespace MenuTable;
    using Options = CommandManager::Options;
 

src/menus/FileMenus.cpp

@@ -143,6 +143,7 @@ struct Handler : CommandHandlerObject {
 
 void OnNew(const CommandContext &context )
 {
+   (void)context;// Compiler food
    CreateNewAudacityProject();
 }
 

src/menus/LabelMenus.cpp

@@ -575,6 +575,7 @@ static CommandHandlerObject &findCommandHandler(AudacityProject &) {
 
 MenuTable::BaseItemPtr LabelEditMenus( AudacityProject &project )
 {
+   (void)project;//Compiler food
    using namespace MenuTable;
    using Options = CommandManager::Options;
 

src/tracks/playabletrack/notetrack/ui/NoteTrackSliderHandles.cpp

@@ -46,6 +46,7 @@ float VelocitySliderHandle::GetValue()
 UIHandle::Result VelocitySliderHandle::SetValue
 (AudacityProject *pProject, float newValue)
 {
+   (void)pProject;//Compiler food
    auto pTrack = GetNoteTrack();
 
    if (pTrack) {

src/tracks/playabletrack/wavetrack/ui/WaveTrackSliderHandles.cpp

@@ -43,6 +43,7 @@ float GainSliderHandle::GetValue()
 UIHandle::Result GainSliderHandle::SetValue
 (AudacityProject *pProject, float newValue)
 {
+   (void)pProject;//Compiler food
    auto pTrack = GetWaveTrack();
 
    if (pTrack) {
@@ -118,6 +119,7 @@ float PanSliderHandle::GetValue()
 
 UIHandle::Result PanSliderHandle::SetValue(AudacityProject *pProject, float newValue)
 {
+   (void)pProject;//Compiler food
    using namespace RefreshCode;
    Result result = RefreshNone;
    auto pTrack = GetWaveTrack();