Path: (web uri) - split-and-decode-uri-path must preserve plus characters

[Brent]

Hi all,

Attached is a patch to to correct the behaviour of 
split-and-decode-uri-path in uri.scm from guile 2.0.9.

Fault
-------
The faulty behaviour is:

    (use-modules (web uri))
    (split-and-decode-uri-path "xxx/abc+def/yyy")    → ("xxx" "abc def" 
"yyy")

As can be seen, the plus has been erroneously converted to a space.

The correct behaviour is:

    (split-and-decode-uri-path "xxx/abc+def/yyy")    → ("xxx" "abc+def" 
"yyy")

Analysis
------------
The fault is actually in the uri-decode function invoked by 
split-and-decode-uri-path:
it has special logic to check for a #\+ character and convert it to a space.

The reason for this is that uri-decode is also used to decode query 
string for
application/x-www-form-urlencoded requests where spaces are encoded by 
the client
on submission to plus characters.

(see http://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.1)

Fix
---
The fix is to extend uri-decode with a new keyword argument #:form? that 
is defaulted
to #t. This provides backward compatibility.

split-and-decode-uri-path is modified to call uri-decode with #:form? 
set to #f.

Motivation
---------------
This patch is motivated by the need to embed ISO 8601 timestamps with 
time zones
into URLs:

eg. GET http:/foo.org/aaa/bbb/20140717T072233+0200/xxx/yyy


Please consider this for inclusion.


Thanks,

Brent

fix-web-uri-decode-plus-to-space.patch
Description: Text Data