Rename QgsProject::projectDirty to isDirtyChanged

Also show unsaved status in title bar even when project has
not been first saved

python/core/qgsproject.sip.in

@@ -1140,7 +1140,7 @@ advertised by this signal.
 :param layers: List of QgsMapLayer which were added to the legend.
 %End
 
-    void projectDirty( const bool dirty );
+    void isDirtyChanged( bool dirty );
 %Docstring
 Emitted when the project dirty status changes.
 

src/app/layout/qgslayoutdesignerdialog.cpp

@@ -751,7 +751,7 @@ QgsLayoutDesignerDialog::QgsLayoutDesignerDialog( QWidget *parent, Qt::WindowFla
   //listen out to status bar updates from the view
   connect( mView, &QgsLayoutView::statusMessage, this, &QgsLayoutDesignerDialog::statusMessageReceived );
 
-  connect( QgsProject::instance(), &QgsProject::projectDirty, this, &QgsLayoutDesignerDialog::updateWindowTitle );
+  connect( QgsProject::instance(), &QgsProject::isDirtyChanged, this, &QgsLayoutDesignerDialog::updateWindowTitle );
 }
 
 QgsAppLayoutDesignerInterface *QgsLayoutDesignerDialog::iface()

src/app/qgisapp.cpp

@@ -476,10 +476,10 @@ static void setTitleBarText_( QWidget &qgisApp )
   }
   if ( !caption.isEmpty() )
   {
-    if ( QgsProject::instance()->isDirty() )
-      caption.prepend( '*' );
     caption += " - ";
   }
+  if ( QgsProject::instance()->isDirty() )
+    caption.prepend( '*' );
 
   caption += QgisApp::tr( "QGIS" );
 
@@ -754,7 +754,7 @@ QgisApp::QgisApp( QSplashScreen *splash, bool restorePlugins, bool skipVersionCh
   mMapCanvas->setCanvasColor( QColor( myRed, myGreen, myBlue ) );
   endProfile();
 
-  connect( QgsProject::instance(), &QgsProject::projectDirty, this, [ = ] { setTitleBarText_( *this ); } );
+  connect( QgsProject::instance(), &QgsProject::isDirtyChanged, this, [ = ] { setTitleBarText_( *this ); } );
 
   // what type of project to auto-open
   mProjOpen = settings.value( QStringLiteral( "qgis/projOpenAtLaunch" ), 0 ).toInt();

src/core/qgsproject.cpp

@@ -414,7 +414,7 @@ bool QgsProject::isDirty() const
 void QgsProject::setDirty( bool b )
 {
   mDirty = b;
-  emit projectDirty( mDirty );
+  emit isDirtyChanged( mDirty );
 }
 
 void QgsProject::setFileName( const QString &name )

src/core/qgsproject.h

@@ -1097,7 +1097,7 @@ class CORE_EXPORT QgsProject : public QObject, public QgsExpressionContextGenera
      * \since QGIS 3.2
      *
      */
-    void projectDirty( const bool dirty );
+    void isDirtyChanged( bool dirty );
 
   public slots: