Add sensible default mode to directory creation

Fix #2632

htdocs/core/lib/functions.lib.php

@@ -3727,10 +3727,10 @@ function get_exdir($num,$level=3,$alpha=0,$withoutslash=0)
  *
  *	@param	string	$dir		Directory to create (Separator must be '/'. Example: '/mydir/mysubdir')
  *	@param	string	$dataroot	Data root directory (To avoid having the data root in the loop. Using this will also lost the warning on first dir PHP has no permission when open_basedir is used)
- *  @param	int		$newmask	Mask for new file (0 by default means $conf->global->MAIN_UMASK). Example: '0444'
+ *  @param	int		$newmask	Mask for new file (Defaults to $conf->global->MAIN_UMASK or 0755 if unavailable). Example: '0444'
  *	@return int         		< 0 if KO, 0 = already exists, > 0 if OK
  */
-function dol_mkdir($dir, $dataroot='', $newmask=0)
+function dol_mkdir($dir, $dataroot='', $newmask=null)
 {
 	global $conf;
 
@@ -3768,7 +3768,9 @@ function dol_mkdir($dir, $dataroot='', $newmask=0)
 
 				umask(0);
 				$dirmaskdec=octdec($newmask);
-				if (empty($newmask) && ! empty($conf->global->MAIN_UMASK)) $dirmaskdec=octdec($conf->global->MAIN_UMASK);
+				if (empty($newmask)) {
+					$dirmaskdec = empty( $conf->global->MAIN_UMASK ) ? octdec( '0755' ) : octdec( $conf->global->MAIN_UMASK );
+				}
 				$dirmaskdec |= octdec('0111');  // Set x bit required for directories
 				if (! @mkdir($ccdir_osencoded, $dirmaskdec))
 				{