Windows: convert the spawned command to locale encoding

Converting to locale encoding is required to allows non-ASCII
characters in the command, e.g. in the file names.

src/win32.c

@@ -1038,6 +1038,7 @@ gboolean win32_spawn(const gchar *dir, gchar **argv, gchar **env, GSpawnFlags fl
 	gchar *tmp_file = create_temp_file();
 	gchar *tmp_errfile = create_temp_file();
 	gchar *command;
+	gchar *locale_command;
 
 	if (env != NULL)
 	{
@@ -1052,9 +1053,12 @@ gboolean win32_spawn(const gchar *dir, gchar **argv, gchar **env, GSpawnFlags fl
 	command = g_strjoinv(" ", argv);
 	SETPTR(command, g_strdup_printf("cmd.exe /S /C \"%s >%s 2>%s\"",
 		command, tmp_file, tmp_errfile));
+	locale_command = g_locale_from_utf8(command, -1, NULL, NULL, NULL);
+	if (! locale_command)
+		locale_command = g_strdup(command);
 	geany_debug("WIN32: actually running command:\n%s", command);
 	g_chdir(dir);
-	ret = system(command);
+	ret = system(locale_command);
 	/* the command can return -1 as an exit code, so check errno also */
 	fail = ret == -1 && errno;
 	if (!fail)
@@ -1068,6 +1072,7 @@ gboolean win32_spawn(const gchar *dir, gchar **argv, gchar **env, GSpawnFlags fl
 		g_set_error_literal(error, G_SPAWN_ERROR, errno, g_strerror(errno));
 
 	g_free(command);
+	g_free(locale_command);
 	g_unlink(tmp_file);
 	g_free(tmp_file);
 	g_unlink(tmp_errfile);