LOCALE_IO: replace the call to setlocale by a call to wxLocale to switch to "C" locale.

Previously we call only setlocale( xx, "C" ), but it was not enough on Windows.
Now we call wxLocale("C")
wxLocale calls setlocale, but also make some others initialization in wxWidgets.
It fixes some issues related to comma versus point as fp separator.
Especially wxWidgets warnings are no longer thrown, and a one case of incorrect
conversion is fixed.

common/common.cpp

@@ -1,9 +1,9 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2014-2019 Jean-Pierre Charras, jp.charras at wanadoo.fr
+ * Copyright (C) 2014-2020 Jean-Pierre Charras, jp.charras at wanadoo.fr
  * Copyright (C) 2008 Wayne Stambaugh <stambaughw@gmail.com>
- * Copyright (C) 1992-2019 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2020 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -55,34 +55,42 @@ using KIGFX::COLOR4D;
  *       application class.
  */
 
+// When reading/writing files, we need to swtich to setlocale( LC_NUMERIC, "C" ).
+// Works fine to read/write files with floating point numbers.
+// We can call setlocale( LC_NUMERIC, "C" ) of wxLocale( "C", "C", "C", false )
+// wxWidgets discourage a direct call to setlocale
+// Previouly, we called setlocale( LC_NUMERIC, "C" )
+// The old code will be removed when calling wxLocale( "C", "C", "C", false ) is fully tested
+#define USE_WXLOCALE 1      /* 0 to call setlocale, 1 to call wxLocale */
 
+// On Windows, when using setlocale, a wx alert is generated
+// in some cases (reading a bitmap for instance)
+// So we disable alerts during the time a file is read or written
+#if !USE_WXLOCALE
 #if defined( _WIN32 ) && defined( DEBUG )
 // a wxAssertHandler_t function to filter wxWidgets alert messages when reading/writing a file
 // when switching the locale to LC_NUMERIC, "C"
 // It is used in class LOCALE_IO to hide a useless (in kicad) wxWidgets alert message
 void KiAssertFilter( const wxString &file, int line,
-                                  const wxString &func, const wxString &cond,
-                                  const wxString &msg)
+                     const wxString &func, const wxString &cond,
+                     const wxString &msg)
 {
     if( !msg.Contains( "Decimal separator mismatch" ) )
         wxTheApp->OnAssertFailure( file.c_str(), line, func.c_str(), cond.c_str(), msg.c_str() );
 }
 #endif
+#endif
 
 
 std::atomic<unsigned int> LOCALE_IO::m_c_count( 0 );
-
-
-// Note on Windows, setlocale( LC_NUMERIC, "C" ) works fine to read/write
-// files with floating point numbers, but generates a overzealous wx alert
-// in some cases (reading a bitmap for instance)
-// So we disable alerts during the time a file is read or written
-
-LOCALE_IO::LOCALE_IO()
+LOCALE_IO::LOCALE_IO() : m_wxLocale( nullptr )
 {
     // use thread safe, atomic operation
     if( m_c_count++ == 0 )
     {
+#if USE_WXLOCALE
+        m_wxLocale = new wxLocale( "C", "C", "C", false );
+#else
         // Store the user locale name, to restore this locale later, in dtor
         m_user_locale = setlocale( LC_NUMERIC, nullptr );
 #if defined( _WIN32 ) && defined( DEBUG )
@@ -91,6 +99,7 @@ LOCALE_IO::LOCALE_IO()
 #endif
         // Switch the locale to C locale, to read/write files with fp numbers
         setlocale( LC_NUMERIC, "C" );
+#endif
     }
 }
 
@@ -101,10 +110,15 @@ LOCALE_IO::~LOCALE_IO()
     if( --m_c_count == 0 )
     {
         // revert to the user locale
+#if USE_WXLOCALE
+        delete m_wxLocale;      // Deleting m_wxLocale restored previous locale
+        m_wxLocale = nullptr;
+#else
         setlocale( LC_NUMERIC, m_user_locale.c_str() );
 #if defined( _WIN32 ) && defined( DEBUG )
         // Enable wxWidgets alerts
         wxSetDefaultAssertHandler();
+#endif
 #endif
     }
 }

include/common.h

@@ -1,10 +1,10 @@
 /*
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
- * Copyright (C) 2014-2019 Jean-Pierre Charras, jp.charras at wanadoo.fr
+ * Copyright (C) 2014-2020 Jean-Pierre Charras, jp.charras at wanadoo.fr
  * Copyright (C) 2007-2015 SoftPLC Corporation, Dick Hollenbeck <dick@softplc.com>
  * Copyright (C) 2008 Wayne Stambaugh <stambaughw@gmail.com>
- * Copyright (C) 1992-2019 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2020 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -110,6 +110,7 @@ private:
     // The locale in use before switching to the "C" locale
     // (the locale can be set by user, and is not always the system locale)
     std::string m_user_locale;
+    wxLocale*   m_wxLocale;
 };
 
 /**