merge r4965 from branch 2.0 to trunk

bug 1047 fixed: avoid warnings when the creation date is 0000-00-00 (which
happens when date_creation comes from corrupted EXIF)

bug 859 fixed: at display time only. Piwigo still inserts wrong date in the
database, to be fixed later.


git-svn-id: http://piwigo.org/svn/trunk@4966 68402e56-0260-453c-a942-63ccdbb3a9ee

include/functions.inc.php

@@ -516,6 +516,11 @@ function format_date($date, $show_time = false)
 {
   global $lang;
 
+  if (strpos($date, '0') == 0)
+  {
+    return l10n('N/A');
+  }
+
   $ymdhms = array();
   $tok = strtok( $date, '- :');
   while ($tok !== false)