Alexander Pettelkau schrieb:
> Bug #1251: gsub problem
> http://redmine.ruby-lang.org/issues/show/1251
> 
> Author: Alexander Pettelkau
> Status: Open, Priority: Normal
> Category: core, Target version: 1.9.1
> ruby -v: ruby 1.9.1p0 (2009-01-30 revision 21907) [i386-darwin9.6.0]
> 
> I wanted to replace "\" with "\\" in the string "\TEST":
> 
> s="\\TEST"
> puts s    # Output --> "\TEST"
> s.gsub!("\\","\\\\")
> puts s    # Output --> "\TEST"
>           # but EXPECTED Output "\\TEST"
> 
> 
> ----------------------------------------
> http://redmine.ruby-lang.org
> 
> 
After the first step, the String contains two backslashes. This string 
will be interpreted again, because there can be references to matched 
groups inside (e.g. '\1'). This second interpretation sees a escaped 
backslash (backslash-backslash, which results in one backslash.

I think it should be documented,

Wolfgang Nádasi-Donner