From: Andy Wingo <wingo@igalia.com>
Subject: Re: bug#26013: (srfi srfi-37) chokes on empty string 
parameter
Date: Wed, 19 Apr 2017 17:13:25 +0200

> On Tue 07 Mar 2017 16:34, Thomas Danckaert 
> <post@thomasdanckaert.be> writes:
>
>> It looks like Guile's srfi-37 implementation doesn't process empty
>> string arguments correctly.
>> [...]
>> In srfi/srfi-37.scm:
>>  220: 1 [next-arg]
>> In unknown file:
>>    ?: 0 [string-ref "" 0]
>>
>> ERROR: In procedure string-ref:
>> ERROR: Value out of range: 0
>
> Sounds like the right diagnosis to me.  Want to submit a patch? :)

Well, let me try :)

I don't fully understand the code in srfi-37.scm, but I think the fix 
can be as simple as the attached patch (i.e. first check if the 
argument is empty, otherwise check if it starts with \#-).

I have tried to follow the existing indentation convention, as far as 
I understand it (a mix of tabs and spaces).

Thomas