Portable windows build

If a portable/ folder is next to the libvlccore.dll binary, it will use
it for most configuration and other files.

Close #9751, #2114 and #12679
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/gui/qt4/qt4.cpp

@@ -483,6 +483,15 @@ static void *Thread( void *obj )
 
 
     /* All the settings are in the .conf/.ini style */
+#ifdef _WIN32
+    char *cConfigDir = config_GetUserDir( VLC_CONFIG_DIR );
+    QString configDir = cConfigDir;
+    free( cConfigDir );
+    if( configDir.endsWith( "\\vlc" ) )
+        configDir.chop( 4 ); /* the "\vlc" dir is added again by QSettings */
+    QSettings::setPath( QSettings::IniFormat, QSettings::UserScope, configDir );
+#endif
+
     p_intf->p_sys->mainSettings = new QSettings(
 #ifdef _WIN32
             QSettings::IniFormat,

src/win32/dirs.c

@@ -87,6 +87,21 @@ static char *config_GetShellDir (int csidl)
 
 static char *config_GetAppDir (void)
 {
+    /* if portable directory exists, use it */
+    TCHAR path[MAX_PATH];
+    if (GetModuleFileName (NULL, path, MAX_PATH))
+    {
+        TCHAR *lastDir = _tcsrchr (path, '\\');
+        if (lastDir)
+        {
+            _tcscpy (lastDir + 1, TEXT("portable"));
+            DWORD attrib = GetFileAttributes (path);
+            if (attrib != INVALID_FILE_ATTRIBUTES &&
+                    (attrib & FILE_ATTRIBUTE_DIRECTORY))
+                return FromT (path);
+        }
+    }
+
     char *psz_dir;
     char *psz_parent = config_GetShellDir (CSIDL_APPDATA);