Roland Perry wrote:
In message
, at 15:56:26 on Wed, 28 May 2014, Recliner remarked:
White space is specifically allowed in urls; doubly so if enclosed in delimiters.

News to me, and to my newsreader.

True nevertheless.

Only if encoded as %20 or +. I don't think an actual space is allowed.

rfc3986:

In some cases, extra whitespace (spaces, line-breaks, tabs, etc.) may
have to be added to break a long URI across lines. The whitespace
should be ignored when the URI is extracted.

...

Using angle brackets around each URI is especially recommended as
a delimiting style for a reference that contains embedded whitespace.

So whitespace is allowed in *text* representations, such as usenet
postings. *After* the url has been extracted from the text, *then* the
spaces should be encoded (before being passed to the browser).

And the URL you (or Agent) presented to Firefox still had the embedded
space, rather than a %20, hence the problem. In my case, I just deleted the
unwanted space, and it worked.