Does CF really auto-decode URL parameters passed to a page?

Question

CF docs and livedocs state that:
quote:
ColdFusion automatically decodes URL parameters that are
passed to a page
(for example, see the URLEncodedFormat tag description, last
sentence of opening paragraph)
However, if you have a url-encoded url parameters, as in
?var1=1%26var2=2 (%26 is url-encoded equivalent of &), and in
your page you try to validate url parameters with <cfparam
type="integer" name="url.var1"> or with isvalid("integer",
url.var1) function, the validation will fail! Apparently, inside at
least this tag and function Cf does not automatically decode url
parameters... it sees the var1 declaration, but sees its value to
be not 1, but 1&var2=2, which surely fails validation against
type "integer"....
This behaviour has been brought up in these forums several
times now, but nobody has been able to explain how this relates to
the CF docs statement... Any ideas, anyone? Is this an expected
behaviour? Are the docs wrong? Does 'parameter', as in "url
parameters", refer only to specific parts of query string and does
not include url var name/value pairs separator? Apparently the same
happens if you have "=" sign url-encoded, too...

Answer 1

I will have to think on this, do some reading and try some
experiments.
But my first thought is that this is expected behavior. I
would
propose the purpose of URL encoding the ampersand(&) is
so that it will
be considered a part of a value, not its usual role of
name-value pair
separator. So in my mind this is the way it is supposed to
work.
val1=1&val2=2 : val1 is 1 and val2 is 2
val1=1%26var2=2 : val1 is '1&var2' or '1&var2=2'
I will have to explore this further.