Recursively calling a bash script goes undetected and eats all system memory

[Diggory Hardy]

Hello,

With a simple script such as that below, bash can enter an infinite loop of 
eating memory until the system is rendered unusable:

#!/bin/bash
PATH=~
infinitely-recurse

Save this as infinitely-recurse in your home directory and run - and make sure 
you kill it pretty quick. OK, so an obvious bug when put like this, though it 
bit me recently (mistakenly using PATH as an ordinary variable and having a 
script with the same name as a system program). Would it not be simple to add 
some kind of protection against this — say don't let a script call itself more 
than 100 times?

Thanks,
Diggory