[pdftex] Regression: Wrong spacing with explicit space character of different font

[Heiko Oberdiek]

On 21.05.2014 23:53, Ross Moore wrote:

> I can confirm that the same problem exists with the experimental
> version that I have been using for tagged-PDF, for which the
> fake spaces were first developed.
> 
> viz.
> 
> This is pdfTeX, Version 3.1415926-1.40.11+tagged-pdf (TeX Live 2010)

Thanks for checking.
2010, so old?

Thanh has already written a fix. :-)

> Heiko,
> can I ask why you use such a construction, which seems
> to be deliberately hiding the space?
> Is it to fool a system that automatically extracts email
> addresses from a PDF, by detecting the '@' character?

The starting point was to fool the URL detection heuristics of PDF viewers:
  http://tex.stackexchange.com/a/179587/16967

I could fool the heuristics of AR9/Linux with

    \font\ph=phvr8r

    abc@\rlap{\ph\char32}server.com

But not with

    abc@\rlap{\pdffakespace}server.com

Then AR9/Linux wants to link to "mailto:abc@ server.com"

Yours sincerely
  Heiko Oberdiek