Re: small fix of libtool.m4

[Christian]

thx Eric for taking a look at my patch.

it seems to be a good idea to use ‘rm -f’ and i also think it looks like $RM 
should already be set to ‘rm -f’. but i don’t get why it should fail than.
what i’ll do next is check if $RM really is set to ‘rm -f’ using a  debug 
print. couldn’t do it right now, just in case it might be set different for 
some reason.

> On May 6, 2016, at 7:48 AM, Eric Blake <address@hidden> wrote:
> 
> On 05/05/2016 11:22 PM, Christian wrote:
>> So i found that if you’re running ‘./configure’ on a project that depends on 
>> libtool, it might happen that the script will end up with the following 
>> error: 
>> “/bin/rm: cannot remove 'libtoolT': No such file or directory”. I did some 
> 
>> 
>>     cfgfile=${ofile}T
>>     trap "$RM \"$cfgfile\"; exit 1" 1 2 15
>> -    $RM "$cfgfile"
>> +    if test -e "$cfgfile" ; then
>> +      $RM "$cfgfile"
>> +    fi
> 
> That's a TOCTTOU data race.  Wouldn't it be better to just use 'rm -f'?
> In fact, isn't $RM supposed to be including -f automatically?
> 
> -- 
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
>