A safer File.readln

[Markus Laker via Digitalmars-d]

On Monday, 23 January 2017 at 10:44:50 UTC, Shachar Shemesh wrote:
> Of course, if, instead of 50% we increase by less (say, 20%), 
> we could reuse previously used memory even sooner.

Yes, you're right, of course: expansion of strings and other 
arrays is a classic time-versus-space trade-off.  However, 
expanding strings more slowly is a much bigger change than I have 
the D experience or credentials to suggest.  And I don't think it 
really solves the problem: it just requires the attacker to wait 
another few seconds for /dev/zero to deliver enough data to fill 
up memory.  A simple length-check in readln, in contrast, would 
prevent an attacker from flooding us with data in the first place.

Markus