From a107f7ce5b632dcccf88ab55a60b3ae56c2d986e Mon Sep 17 00:00:00 2001
From: Jon Evans <jon@craftyjon.com>
Date: Mon, 20 Jul 2020 19:39:59 -0400
Subject: [PATCH] Fix a few issues with legacy project loading

- Prevent crash on project tree for "Empty project" item
- Correctly handle loading of legacy projects in tree view
- Fix an issue where legacy projects would not get saved

Fixes https://gitlab.com/kicad/code/kicad/-/issues/4944
---
 common/settings/json_settings.cpp |  3 ++-
 kicad/tree_project_frame.cpp      | 23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/common/settings/json_settings.cpp b/common/settings/json_settings.cpp
index c4e69d33f6..8e78dae033 100644
--- a/common/settings/json_settings.cpp
+++ b/common/settings/json_settings.cpp
@@ -311,7 +311,8 @@ bool JSON_SETTINGS::SaveToFile( const std::string& aDirectory, bool aForce )
         return false;
     }
 
-    if( !path.IsFileWritable() )
+    if( ( path.FileExists() && !path.IsFileWritable() ) ||
+        ( !path.FileExists() && !path.IsDirWritable() ) )
     {
         wxLogTrace( traceSettings, "File for %s is read-only; not saving", GetFullFilename() );
         return false;
diff --git a/kicad/tree_project_frame.cpp b/kicad/tree_project_frame.cpp
index 553caf6662..727288a2f1 100644
--- a/kicad/tree_project_frame.cpp
+++ b/kicad/tree_project_frame.cpp
@@ -544,6 +544,7 @@ void TREE_PROJECT_FRAME::ReCreateTreePrj()
         return;
 
     wxFileName fn = pro_dir;
+    bool prjReset = false;
 
     if( !fn.IsOk() )
     {
@@ -551,10 +552,22 @@ void TREE_PROJECT_FRAME::ReCreateTreePrj()
         fn.SetPath( wxStandardPaths::Get().GetDocumentsDir() );
         fn.SetName( NAMELESS_PROJECT );
         fn.SetExt( ProjectFileExtension );
+        prjReset = true;
     }
 
     bool prjOpened = fn.FileExists();
 
+    // We may have opened a legacy project, in which case GetProjectFileName will return the
+    // name of the migrated (new format) file, which may not have been saved to disk yet.
+    if( !prjOpened && !prjReset )
+    {
+        fn.SetExt( LegacyProjectFileExtension );
+        prjOpened = fn.FileExists();
+
+        // Set the ext back so that in the tree view we see the (not-yet-saved) new file
+        fn.SetExt( ProjectFileExtension );
+    }
+
     // root tree:
     m_root = m_TreeProject->AddRoot( fn.GetFullName(), TREE_ROOT, TREE_ROOT );
     m_TreeProject->SetItemBold( m_root, true );
@@ -631,6 +644,16 @@ void TREE_PROJECT_FRAME::OnRight( wxTreeEvent& Event )
 
     for( TREEPROJECT_ITEM* item_data : tree_data )
     {
+        // Check for empty project
+        if( !item_data )
+        {
+            can_switch_to_project = false;
+            can_edit = false;
+            can_rename = false;
+            can_print = false;
+            continue;
+        }
+
         int      tree_id = item_data->GetType();
         wxString full_file_name = item_data->GetFileName();