Issue #655048 by Gábor Hojtsy, gumanist, intuited, Albert Volkman: Plural...

Issue #655048 by Gábor Hojtsy, gumanist, intuited, Albert Volkman: Plural formula information was blanked when importing a poorly-formed .po file.

includes/locale.inc

@@ -1293,14 +1293,11 @@ function _locale_import_one_string($op, $value = NULL, $mode = NULL, $lang = NUL
           // data untouched or if we don't have an existing plural formula.
           $header = _locale_import_parse_header($value['msgstr']);
 
-          // Get the plural formula and update in database.
+          // Get and store the plural formula if available.
           if (isset($header["Plural-Forms"]) && $p = _locale_import_parse_plural_forms($header["Plural-Forms"], $file->filename)) {
             list($nplurals, $plural) = $p;
             db_query("UPDATE {languages} SET plurals = %d, formula = '%s' WHERE language = '%s'", $nplurals, $plural, $lang);
           }
-          else {
-            db_query("UPDATE {languages} SET plurals = %d, formula = '%s' WHERE language = '%s'", 0, '', $lang);
-          }
         }
         $headerdone = TRUE;
       }