confused about %config file directive

[Sheldon Plankton]

Hi,

I want to create two RPMs.  The first RPM install apache and I call it
my-apache.rpm and a second my-apache-config.rpm.  my-apache.rpm
installs apache and my-apache-config.rpm adds some files like
/usr/local/apache/conf/extra/my.conf but I also want it to overwrite
my-apache.rpm's /usr/local/apache/conf/httpd.conf with a custom
httpd.conf

In my-apache.spec I used these lines:

%files
...
%config /apps/SD/apache/conf/httpd.conf

but when I attempt to install the RPM via YUM I get an error

Transaction Check Error:
  file /usr/local/apache/conf/httpd.conf from install of
my-apache-config conflicts with file from package my-apache

I tried not using the %config directive and had the same result.  How
can I specify in my spec file that it is OK to overwrite a file?