From 01265ace66a360185d2581da7c9d27a974050c5f Mon Sep 17 00:00:00 2001
From: Oskar Wallgren <oskar.wallgren13@gmail.com>
Date: Fri, 17 Nov 2017 02:03:49 +0100
Subject: [PATCH] Default project when cancelling project loading (#3941)

Default project when cancelling project loading

If a user isn't aware that the loading of a project has been
cancelled, it may be in an incomplete state. Saving such a project
will overwrite the original file and result in data loss. This is
solved by loading the default project on cancelling project loading.

Add Mixer::clearNewPlayHandles() to prevent crash when cancelling
loading of a single streamed instrument.
---
 include/Mixer.h             |  1 +
 include/Song.h              | 13 +++++++++++++
 src/core/Mixer.cpp          | 14 ++++++++++++++
 src/core/Song.cpp           | 12 ++++++++++--
 src/core/TrackContainer.cpp | 10 ++++++++++
 5 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/include/Mixer.h b/include/Mixer.h
index 8368e8434..1c3780b1b 100644
--- a/include/Mixer.h
+++ b/include/Mixer.h
@@ -155,6 +155,7 @@ public:
 
 	void initDevices();
 	void clear();
+	void clearNewPlayHandles();
 
 
 	// audio-device-stuff
diff --git a/include/Song.h b/include/Song.h
index b8879ad9b..0ba8a3503 100644
--- a/include/Song.h
+++ b/include/Song.h
@@ -33,6 +33,7 @@
 #include "TrackContainer.h"
 #include "Controller.h"
 #include "MeterModel.h"
+#include "Mixer.h"
 #include "VstSyncController.h"
 
 
@@ -229,6 +230,17 @@ public:
 		return m_loadingProject;
 	}
 
+	void loadingCancelled()
+	{
+		m_isCancelled = true;
+		Engine::mixer()->clearNewPlayHandles();
+	}
+
+	bool isCancelled()
+	{
+		return m_isCancelled;
+	}
+
 	bool isModified() const
 	{
 		return m_modified;
@@ -358,6 +370,7 @@ private:
 	volatile bool m_paused;
 
 	bool m_loadingProject;
+	bool m_isCancelled;
 
 	QStringList m_errors;
 
diff --git a/src/core/Mixer.cpp b/src/core/Mixer.cpp
index c99d3ab8c..ed8d04a6c 100644
--- a/src/core/Mixer.cpp
+++ b/src/core/Mixer.cpp
@@ -501,6 +501,20 @@ void Mixer::clear()
 
 
 
+void Mixer::clearNewPlayHandles()
+{
+	requestChangeInModel();
+	for( LocklessListElement * e = m_newPlayHandles.popList(); e; )
+	{
+		LocklessListElement * next = e->next;
+		m_newPlayHandles.free( e );
+		e = next;
+	}
+	doneChangeInModel();
+}
+
+
+
 // removes all play-handles. this is necessary, when the song is stopped ->
 // all remaining notes etc. would be played until their end
 void Mixer::clearInternal()
diff --git a/src/core/Song.cpp b/src/core/Song.cpp
index 01071668c..5f8e75320 100644
--- a/src/core/Song.cpp
+++ b/src/core/Song.cpp
@@ -86,6 +86,7 @@ Song::Song() :
 	m_playing( false ),
 	m_paused( false ),
 	m_loadingProject( false ),
+	m_isCancelled( false ),
 	m_playMode( Mode_None ),
 	m_length( 0 ),
 	m_patternToPlay( NULL ),
@@ -1074,7 +1075,7 @@ void Song::loadProject( const QString & fileName )
 		}
 	}
 
-	while( !node.isNull() )
+	while( !node.isNull() && !isCancelled() )
 	{
 		if( node.isElement() )
 		{
@@ -1133,6 +1134,13 @@ void Song::loadProject( const QString & fileName )
 
 	emit projectLoaded();
 
+	if( isCancelled() )
+	{
+		m_isCancelled = false;
+		createNewProject();
+		return;
+	}
+
 	if ( hasErrors())
 	{
 		if ( gui )
@@ -1278,7 +1286,7 @@ void Song::saveControllerStates( QDomDocument & doc, QDomElement & element )
 void Song::restoreControllerStates( const QDomElement & element )
 {
 	QDomNode node = element.firstChild();
-	while( !node.isNull() )
+	while( !node.isNull() && !isCancelled() )
 	{
 		Controller * c = Controller::create( node.toElement(), this );
 		Q_ASSERT( c != NULL );
diff --git a/src/core/TrackContainer.cpp b/src/core/TrackContainer.cpp
index 6e406b0a9..6877e6b1f 100644
--- a/src/core/TrackContainer.cpp
+++ b/src/core/TrackContainer.cpp
@@ -33,12 +33,14 @@
 #include "AutomationTrack.h"
 #include "BBTrack.h"
 #include "BBTrackContainer.h"
+#include "embed.h"
 #include "TrackContainer.h"
 #include "InstrumentTrack.h"
 #include "Song.h"
 
 #include "GuiApplication.h"
 #include "MainWindow.h"
+#include "TextFloat.h"
 
 TrackContainer::TrackContainer() :
 	Model( NULL ),
@@ -110,6 +112,14 @@ void TrackContainer::loadSettings( const QDomElement & _this )
 						QEventLoop::AllEvents, 100 );
 			if( pd->wasCanceled() )
 			{
+				if ( gui )
+				{
+					TextFloat::displayMessage( tr( "Loading cancelled" ),
+					tr( "Project loading was cancelled." ),
+					embed::getIconPixmap( "project_file", 24, 24 ),
+					2000 );
+				}
+				Engine::getSong()->loadingCancelled();
 				break;
 			}
 		}