Catch exception when creating app settings objects

These settings objects could be created in a constructor/destructor
so we should catch the exception since those are noexcept.

Also change the settings trace to match the other kicad traces
as KICAD_SETTINGS

common/project/project_file.cpp

@@ -28,7 +28,6 @@
 #include <wx/config.h>
 #include <wx/log.h>
 
-extern const char* traceSettings;
 
 ///! Update the schema version whenever a migration is required
 const int projectFileSchemaVersion = 1;

common/settings/color_settings.cpp

@@ -25,8 +25,6 @@
 #include <settings/settings_manager.h>
 
 
-extern const char* traceSettings;
-
 ///! Update the schema version whenever a migration is required
 const int colorsSchemaVersion = 1;
 

common/settings/common_settings.cpp

@@ -28,9 +28,6 @@
 using KIGFX::MOUSE_DRAG_ACTION;
 
 
-extern const char* traceSettings;
-
-
 ///! Update the schema version whenever a migration is required
 const int commonSchemaVersion = 1;
 

common/settings/json_settings.cpp

@@ -33,8 +33,7 @@
 #include <wx/debug.h>
 #include <wx/filename.h>
 
-extern const char* traceSettings;
-
+const wxChar* const traceSettings = wxT( "KICAD_SETTINGS" );
 
 JSON_SETTINGS::JSON_SETTINGS( const wxString& aFilename, SETTINGS_LOC aLocation,
                               int aSchemaVersion, bool aCreateIfMissing, bool aCreateIfDefault,

common/settings/nested_settings.cpp

@@ -22,8 +22,6 @@
 
 #include <settings/nested_settings.h>
 
-extern const char* traceSettings;
-
 
 NESTED_SETTINGS::NESTED_SETTINGS( const std::string& aName, int aVersion, JSON_SETTINGS* aParent,
                                   const std::string& aPath ) :

common/settings/settings_manager.cpp

@@ -41,12 +41,6 @@
 #include <wildcards_and_files_ext.h>
 
 
-/**
- * Flag to enable settings tracing
- * @ingroup trace_env_vars
- */
-const char* traceSettings = "SETTINGS";
-
 
 /// Project settings path will be <projectname> + this
 #define PROJECT_BACKUPS_DIR_SUFFIX wxT( "-backups" )

include/settings/json_settings.h

@@ -32,6 +32,14 @@ class NESTED_SETTINGS;
 class PARAM_BASE;
 class SETTINGS_MANAGER;
 
+/**
+ * Flag to enable debug output of settings operations and management.
+ *
+ * Use "KICAD_SETTINGS" to enable.
+ *
+ * @ingroup trace_env_vars
+ */
+extern const wxChar* const traceSettings;
 
 enum class SETTINGS_LOC {
     USER,       ///< The main config directory (e.g. ~/.config/kicad/)

include/settings/settings_manager.h

@@ -94,9 +94,21 @@ public:
                                 } );
 
         if( it != m_settings.end() )
+        {
             ret = dynamic_cast<AppSettings*>( it->get() );
+        }
         else
-            ret = static_cast<AppSettings*>( RegisterSettings( new AppSettings, aLoadNow ) );
+        {
+            try
+            {
+                ret = static_cast<AppSettings*>( RegisterSettings( new AppSettings, aLoadNow ) );
+            }
+            catch( ... )
+            {
+                wxLogTrace( traceSettings, "Unable to create application settings object" );
+            }
+
+        }
 
         return ret;
     }

include/trace_helpers.h

@@ -177,7 +177,7 @@ extern const wxChar* const traceSchSheetPaths;
 /**
  * Flag to enable debug output of environment variable operations.
  *
- * Use "KICAD_ENV_VARS" to enable
+ * Use "KICAD_ENV_VARS" to enable.
  *
  */
 extern const wxChar* const traceEnvVars;

pcbnew/footprint_editor_settings.cpp

@@ -29,8 +29,6 @@
 #include <base_units.h>
 #include <widgets/ui_common.h>
 
-extern const char* traceSettings;
-
 
 ///! Update the schema version whenever a migration is required
 const int fpEditSchemaVersion = 1;