Don't create new project files when opening boards/schematics

Display warning infobar in the board/schematic setup when no project
is loaded, since most of the settings in those dialogs are saved in
the project and not in the board/schematic file.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/4868

common/widgets/paged_dialog.cpp

@@ -24,6 +24,7 @@
 #include <wx/grid.h>
 #include <wx/statline.h>
 
+#include <widgets/infobar.h>
 #include <widgets/paged_dialog.h>
 #include <wx/stc/stc.h>
 
@@ -91,6 +92,9 @@ PAGED_DIALOG::PAGED_DIALOG( wxWindow* aParent, const wxString& aTitle, bool aUse
     auto mainSizer = new wxBoxSizer( wxVERTICAL );
     SetSizer( mainSizer );
 
+    m_infoBar = new WX_INFOBAR( this );
+    mainSizer->Add( m_infoBar, 0, wxEXPAND, 0 );
+
     m_treebook = new PAGED_TREEBOOK( this, wxID_ANY );
     mainSizer->Add( m_treebook, 1, wxEXPAND|wxLEFT|wxTOP, 10 );
 

eeschema/dialogs/dialog_schematic_setup.cpp

@@ -31,6 +31,7 @@
 #include <project/project_file.h>
 #include <project/net_settings.h>
 #include <settings/settings_manager.h>
+#include <widgets/infobar.h>
 #include "dialog_schematic_setup.h"
 #include "panel_eeschema_template_fieldnames.h"
 
@@ -81,6 +82,9 @@ DIALOG_SCHEMATIC_SETUP::DIALOG_SCHEMATIC_SETUP( SCH_EDIT_FRAME* aFrame ) :
 	m_treebook->Connect( wxEVT_TREEBOOK_PAGE_CHANGED,
                          wxBookCtrlEventHandler( DIALOG_SCHEMATIC_SETUP::OnPageChange ), NULL, this );
 
+    if( Prj().IsNullProject() )
+        m_infoBar->ShowMessage( _( "No project is loaded. Changes will not be saved." ) );
+
     FinishDialogSettings();
 }
 

eeschema/files-io.cpp

@@ -284,10 +284,16 @@ bool SCH_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
 
     if( differentProject )
     {
+        if( !Prj().IsNullProject() )
             GetSettingsManager()->SaveProject();
+
         Schematic().SetProject( nullptr );
         GetSettingsManager()->UnloadProject( &Prj() );
-        GetSettingsManager()->LoadProject( pro.GetFullPath() );
+
+        // Do not load a project if one doesn't exist.  This normally happens if we are
+        // standalone and opening a board that has been moved from its project folder.
+        GetSettingsManager()->LoadProject( pro.Exists() ? pro.GetFullPath() : "" );
+
         CreateScreens();
     }
 
@@ -622,7 +628,9 @@ void SCH_EDIT_FRAME::OnImportProject( wxCommandEvent& aEvent )
 
     if( setProject )
     {
+        if( !Prj().IsNullProject() )
             GetSettingsManager()->SaveProject();
+
         Schematic().SetProject( nullptr );
         GetSettingsManager()->UnloadProject( &Prj() );
 
@@ -777,6 +785,7 @@ bool SCH_EDIT_FRAME::SaveProject()
         sheets.emplace_back( std::make_pair( sheet->m_Uuid, sheet->GetName() ) );
     }
 
+    if( !Prj().IsNullProject() )
         Pgm().GetSettingsManager().SaveProject();
 
     if( !Kiface().IsSingle() )

include/widgets/paged_dialog.h

@@ -25,6 +25,9 @@
 #include <wx/treebook.h>
 
 
+class WX_INFOBAR;
+
+
 class PAGED_TREEBOOK : public wxTreebook
 {
 public:
@@ -89,6 +92,7 @@ protected:
     wxButton*   m_auxiliaryButton;
     wxButton*   m_resetButton;
     wxButton*   m_cancelButton;
+    WX_INFOBAR* m_infoBar;
 };
 
 

pcbnew/dialogs/dialog_board_setup.cpp

@@ -35,6 +35,7 @@
 #include <project.h>
 #include <project/project_file.h>
 #include <settings/settings_manager.h>
+#include <widgets/infobar.h>
 #include <wildcards_and_files_ext.h>
 
 #include "dialog_board_setup.h"
@@ -94,6 +95,9 @@ DIALOG_BOARD_SETUP::DIALOG_BOARD_SETUP( PCB_EDIT_FRAME* aFrame ) :
 	m_treebook->Connect( wxEVT_TREEBOOK_PAGE_CHANGED,
                          wxBookCtrlEventHandler( DIALOG_BOARD_SETUP::OnPageChange ), NULL, this );
 
+    if( Prj().IsNullProject() )
+        m_infoBar->ShowMessage( _( "No project is loaded. Changes will not be saved." ) );
+
     FinishDialogSettings();
 }
 

pcbnew/files.cpp

@@ -519,12 +519,14 @@ bool PCB_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
 
         if( pro.GetFullPath() != mgr->Prj().GetProjectFullName() )
         {
+            // calls SaveProject
             SaveProjectSettings();
 
-            mgr->SaveProject( mgr->Prj().GetProjectFullName() );
             mgr->UnloadProject( &mgr->Prj() );
 
-            mgr->LoadProject( pro.GetFullPath() );
+            // Do not load a project if one doesn't exist.  This normally happens if we are
+            // standalone and opening a board that has been moved from its project folder.
+            mgr->LoadProject( pro.Exists() ? pro.GetFullPath() : "" );
         }
     }
 

pcbnew/pcbnew_config.cpp

@@ -227,5 +227,6 @@ void PCB_EDIT_FRAME::SaveProjectSettings()
     SELECTION_FILTER_OPTIONS& filterOpts = GetToolManager()->GetTool<SELECTION_TOOL>()->GetFilter();
     localSettings.m_SelectionFilter      = filterOpts;
 
+    if( !Prj().IsNullProject() )
         GetSettingsManager()->SaveProject();
 }