Doubled slashes in master_sites

[Ryan Schmidt]

On Dec 10, 2007, at 03:44, Randall Wood wrote:

> On 12/10/07, Ryan Schmidt wrote:
>
>> I'm not sure if I'd be in favor of automated stripping of doubled
>> slashes within URLs. It introduces a bit of magic into the
>> master_sites variable, and I think magic should be avoided. And
>> theoretically, a server could behave differently depending on the
>> number of slashes. In practice, though, Apache collapses doubled
>> slashes into a single one, and I don't know of any sites that would
>> rely on double slashes in their download URLs.
>>
>> What do you all think?
>
>
> RFC 2396 (Uniform Resource Identifiers (URI): Generic Syntax)  
> dictates that "URI that are hierarchical in nature use the slash  
> "/" character for separating hierarchical components." so it seems  
> to me that the correct behavior is that null path components (the  
> component between the two slashes in "//") evaluate as a single  
> slash "/".

Thanks for the RFC reference. In particular, section 3.3 "Path  
Component" says that for URLs that have a path component, which all  
our master_sites URLs do, path_segments is made up of one or more  
segments combined with slashes, and a segment is defined as one or  
more pchars (and a slash is not a valid pchar). Therefore I think  
there can be no RFC-compliant URL (having a path component) which has  
a slash next to another slash.


> We should clean that up programatically, since some port  
> maintainers may prefer to leave the extra slashes around the  
> variables for legibility purposes.

I'm prepared to agree to that. But we should consider other variables  
and other situations as well. Some people write "${destroot}/$ 
{prefix}" in some places, when ${prefix} already starts with a slash  
so it should really be written "${destroot}${prefix}". This kind of  
thing occurs all over portfiles, and I don't think there's any  
specific variables we could target for any cleanup operations. So one  
could argue: why should we apply this magic to master_sites when we  
can't apply it elsewhere? Shouldn't we instead educate portfile  
authors that they are concatenating variables together, and to think  
about what those variables contain so that they put slashes where the  
belong and leave them off where they don't belong? In fact... I'll  
bet we can write something into "port lint" to detect and report such  
issues. I might prefer such education over the magic.