[PATCH] do not use gethostbyname() for hostname -s

[Tito]

On Monday 09 December 2013 22:56:34 you wrote:
> 10.12.2013 01:40, Tito wrote:
> > On Monday 09 December 2013 18:56:43 Michael Tokarev wrote:
> >> There's no reason to call gethostbyname() on the value returned
> >> by uname() when asked just for a short name of a host.  This may
> >> also be wrong, when uname is set to one value, but in /etc/hosts
> >> (or elsewhere) the "canonical" name is different.  This is often
> >> the case for localhost entry in /etc/hosts:
> >>
> >>   127.0.0.1	localhost	myname
> >>
> >> With this content of /etc/hosts, and uname being set to myname,
> >> busybox hostname -s will return localhost, while regular
> >> hostname utility returns myname.
> >>
> >> Fix this by not calling gethostbyname() for the simple `hostname -s'
> >> use.
> []
> > Hi,
> > I cannot reproduce the case you show with busybox hostname
> > and /etc/hosts on debian 7:
> 
> Interesting.  Debian7 is exactly the system where I had issues with
> original implementation:
> 
>  $ uname -n
>  gandalf
>  $ head -n1 /etc/hosts
>  127.0.0.1	localhost gandalf
>  $ hostname -s
>  gandalf
>  $ busybox hostname -s
>  localhost
>  $ cat /etc/debian_version
>  7.2
>  $ _
> 
> _My_ /etc/hosts actually has the first line like this:
> 
>  # list real hostname first localhost second or else busybox return wrong name
>  127.0.0.1	gandalf localhost
> 
> and it is dated Sep-2010, so the comment should be from 2010 or before.
> I changed it like shown above for this test.
> 
> Today I discovered the same issue within a freshly installed debian system
> in a virtual machine, the generated /etc/hosts had similar line
> 
>    127.0.0.1 localhost debian
Hi,
looks exatcly like mine.

> 
> which resulted in busybox testsuite to fail (hostname-s-works failure due to
> busybox returning localhost while system hostname returns debian).  This
> failure prompted me to try to fix this finally.

Didn't use the testsuite, but results were different.
The problem is confirmed by the other example. 

> The thing is that busybox hostname calls gethostbyname() on the
> result of uname() call, while system hostname doesn't do this.  But the patch
> shows it too.
> 
> > Even modifying /etc/hosts makes no difference:
> 
> 
> > So now I'm wondering where "(or elsewhere)" could be?
> 
> Well, I don't know what's wrong with our systems.. ;)
> 
> 
> > BTW.: It is better if you attach patches as my or your email client
> > ate the tabs and the patch doesn't apply cleanly.
> 
> Almost always when someone sends patches as attachments, people
> complain saying it is better to send patches inline.  It really
> is easier to reply to inline-patches adding comments to particular
> place in the patch, and here I agree too - it is better to send
> patches inline.

I usually send both, inline for review and attached to preserve TABS etc.

> My client can't ate tabs, -- it is more, I see the tabs in your
> reply exactly as they were in my initial email.  I used
> /usr/sbin/sendmail directly to send my initial email ;)

So the culprit is Kmail's copy and paste....
 
> I just tried saving the patch (whole my email) from thunderbird
> to a temp file and applying it - it applies cleanly to both
> 1.21 version and current git head.  Patch utility strips CRs
> when applying, but that's typical.
> 
> Thanks,
> 
> /mjt
> 

Ciao,
Tito