Backend drush command reparsed by escapeshellcmd() which causes issues if you're using a drush.ini file

Problem

If a Drush backend process creates another backend process then _drush_backend_generate_command() will escape the command using escapeshellcmd().

N.B. This does seem not occur with All-versions-5.x-dev but I'm still testing - taking sometime as the backend invocation has been rewritten :) - looks fantastic.

Steps to reproduce:

• Create a drush.ini in your drush directory (or any other valid location) with the line "memory_limit = 256M" in it
• Create a file called fork.php in some folder with the following contents:
  
  

  <?php
  $fork = drush_get_option('forktest');
  $pid = getmypid();
  $ourFileName = "fork-$fork-pid-$pid";
  $ourFileHandle = fopen($ourFileName, 'w') or die("can't open file");
  fclose($ourFileHandle);
  $fork++;
  if ($fork < 10) {
    drush_backend_fork("scr fork.php --forktest=$fork", array());
  }
  

• Run the command "drush scr fork.php --forktest=1"

This should create 9 files in your current folder starting with fork- however it will only create 2.

This is because the second run of fork.php (the first as a background process) the global variable DRUSH_COMMAND is parsed already with the strings escaped.

System command to invoke 1st fork: (/usr/bin/php -d memory_limit="256M" /home/developer/build/bin/drush/drush.php --php='/usr/bin/php -d memory_limit=\"256M\" ' --quiet --verbose --debug scr 'fork.php' '--forktest=2' --backend 2>&1 &) > /dev/null

System command to invoke 2nd fork: (/usr/bin/php -d memory_limit=\\"256M\\" /home/developer/build/bin/drush/drush.php --php='/usr/bin/php -d memory_limit=\\\"256M\\\" ' --quiet --verbose --debug scr 'fork.php' '--forktest=3' --backend 2>&1 &) > /dev/null

Proposed resolution

There are a couple of possible places to fix this but I'm not sure I really like any solutions I've come up with so far. The patch attached is the best I've come up with so far. Basically it's using PHP'S stripslashes() command to cleanup drush's php option if you're in a backend process.