Conversions fail and block cron

i have some problems with file_cron too.
i have about 6000 files and every file is about 70MB.

first problem was that the variable "cron_last" was never set, because
the cronjob breaks. then i get the problem
in the first sql selection.

.....
// Inspect recemtly updated files which were changed since
// an hour before last cron run.
$recent = 60*60;
$result = db_query("SELECT f.nid, f.v.....


the result was always all files from db cuz cron_last is zero.

My solution
first:
set cron_last before starting conversion or something else

....
if (FILE_CRON) {
$time = time();

// ++++++++++++ add this ++++++++++++
// first set cron_last before something goes wrong
$lastcronrun = (int)variable_get('cron_last', 0);
variable_set('cron_last', $time);
// ++++++++++++ add this ++++++++++++

// If PHP is not in 'safe mode', increase the maximum execution time:
// Setting time limit to zero stops feedapi cron processing.
//if (!ini_get('safe_mode
......

second:
set a limit with constant FILE_CRON_LIMIT_TOTAL
i think that select always all updated files isnt good,
because cron_last can be zero. and then file_convert
is starting always from the beginning of all files.

// Inspect recemtly updated files which were changed since
// an hour before last cron run.
$recent = 60*60;
//++++++ change this +++++
//added Johannes Hahn set max limit her to FILE_CRON_LIMIT_TOTAL
if(FILE_CRON_LIMIT_TOTAL > 0){
$result = db_query("SELECT f.nid, f.vid, f.uri, f.size, f.type AS filemime, n.title AS filename FROM {file_nodes} f INNER JOIN {node} n ON f.nid = n.nid WHERE n.changed > %d ORDER BY n.changed LIMIT %d", $lastcronrun - $recent, FILE_CRON_LIMIT_TOTAL);
}else{
$result = db_query("SELECT f.nid, f.vid, f.uri, f.size, f.type AS filemime, n.title AS filename FROM {file_nodes} f INNER JOIN {node} n ON f.nid = n.nid WHERE n.changed > %d ORDER BY n.changed", $lastcronrun - $recent);
}
//++++++ change this +++++


now my cron job is running well.

rewritten file_cron
please use latest dev release.
dont forget to run update.php

New cron options (/admin/settings/file) are:

• Perform reconvertion on cron runs
• Cron Cycle

may we need better description?