[5.5] Remove unnecessary escapeshellarg call

[misog]

• As mentioned here [Proposal] Do not use escapeshellarg ideas#407 the escapeshellarg function is blocked by some shared hostings.
• Other occurrences of escapeshellarg function were already replaced by "'".str_replace("'", "'\''", $argument)."'".
• Moreover the removed function call in this proposed change is unnecessary and can be replaced by a constant.

[GrahamCampbell]

I don't think we should change this. This code was copied directly from Symfony, and I think we should keep it synced with exactly what they have.

[laurencei]

This code was copied directly from Symfony, I think we should keep it synced with exactly what they have.

@GrahamCampbell Symfony completely changed their escapeArgument() function over a year ago:

https://github.com/symfony/process/blob/master/Process.php#L1533

Personally I think the change above looks good - because its only returning an empty string. If we want to avoid any risk of strange side effects - put it in 5.6 that comes out in a few days.

Alternatively we update the entire function to completely replicate Symfony's new version - but its really close to 5.6 and not much time to test... but if it is working for a large Symfony install base, then it would probably be fine for us?

[misog]

@GrahamCampbell as laurencei said symphony is not using the escapeshellarg anymore. It was even mentioned in context of shared hostings which block the function: symfony/process#14

@laurencei The reason I made this request for 5.5. is that 5.5 is LTS and LTS is very suitable choice for small web apps with limited or none maintenance phase, placed on shared hostings (which usually block escapeshellarg). LTS placed on shared hosting allows to update critical changes quickly (cheaply).

AFAIK this one escapeshellarg('') call which returns constant '""' on Windows [1] is the only escapeshellarg call left in 5.5.

More rewrite to match current symphony approach could be done later in 5.6 or 5.7.

[1] On Windows, escapeshellarg() instead replaces percent signs, exclamation marks (delayed variable substitution) and double quotes with spaces and adds double quotes around the string. https://secure.php.net/manual/en/function.escapeshellarg.php