Description:
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When you open a pipe with popen, work with it an then close, some bytes aren't freed, so when you do that task a lot of times you get out of memory error, (with memory limit) and php crash.... It is working with php cgi mode... I tested it on php 4.x, and 5.0.0...

When you do proc_open is the same. 

When you open a popen and it fails then no memory leak exists.





Reproduce code:
---------------
<?
   printlog("Iniciando");
   for($i=0;$i<10;$i++) {
    if(($fp=popen("ls","r"))==true) {
      printlog("Abierto");
      while(!feof($fp))
        $l=fgets($fp, 8192);
      printlog("Leido");
      fflush($fp);
      pclose($fp);
      printlog("Cerrado");
      unset($fp);
      unset($l);
      printlog("Liberado");
      sleep(1);
    }
   }
   printlog("Terminando");
   die();

function printlog($src) {
    printf("%s (%.03fkb): %s\n",date("r"), memory_get_usage()/1024, rtrim($src));
}
?>

Expected result:
----------------
I expect that when pipe was closed all the memory is freed.

Actual result:
--------------
There are memory leak for about 200 bytes