CPLUS_INCLUDE_PATH confused by colons

[Christoph Bugel]

On Sun 2002-03-24, Nathan Sidwell wrote:
> Neil Booth wrote:
> 
> > These environment variables are a colon-separated list of
> > paths.  So you effectively have an empty-path here, which
> > is being treated as the current directory.  This is a
> > deliberate feature; whether it's a good idea I'm not
> This is a normal feature of the shell's PATH variable treatment.
> (One which I did not know about until 5 seconds ago.) So I guess
> existing practice makes it a '.'

wow that surprised me too!
In my case the problem was triggered by:
CPLUS_INCLUDE_PATH=/usr/lib/qt/include:$CPLUS_INCLUDE_PATH
which evaluates to:
CPLUS_INCLUDE_PATH=/usr/lib/qt/include:

I don't know why gcc (and now also bash..) do this, but it
conflicts with the principle of least surprise. (well, at 
least I was surpised, and apparently whoever wrote that QT
install script was too.)