[Fedora-packaging] Correction to guidelines on %define vs %global

[Panu Matilainen]

Apologies for missing this when the recommendation of %global over %define 
in Fedora guidelines was being discussed, but better late than never...

https://fedoraproject.org/wiki/Packaging/Guidelines#.25global_preferred_over_.25define
says "The two macro defining statements behave the same when they are a 
the top level of rpm's nesting level" but this is not correct:

The body of a %global macro is expanded at definition time, whereas the 
body of a %define is expanded only when used. For many uses it doesn't 
make any difference but identical they are not, even on top level - for 
example see the attached example spec:

$ rpmbuild -bp macroex.spec 2>/dev/null|grep ^case
case1: first - second
case2: second - %{xxx}

Another example of this difference (in case of parametrized macros):
https://bugzilla.redhat.com/show_bug.cgi?id=495658

 	- Panu -
-------------- next part --------------
%global xxx first

%global glob1 %{xxx}
%define def1 %{xxx}

%global glob2 %%{xxx}
%define def2 %%{xxx}

%global xxx second

Name: macroex
Version: 1
Release: 1
License: GPL
Group: Testing
Summary: global vs define

%description
%{summary}

%prep
echo case1: %{glob1} - %{def1}
echo case2: %{glob2} - %{def2}