Description of problem:
hagen:[RHEL-2_1] >make prep                                             
error: syntax error in expression                                       
error: vim.spec:8: parseExpressionBoolean returns -1                    
error: query of specfile vim.spec failed, can't parse                   
error: syntax error in expression                                       
error: vim.spec:8: parseExpressionBoolean returns -1                    
error: query of specfile vim.spec failed, can't parse 

Version-Release number of selected component (if applicable):
rpm-4.5.90-0.git8426.9

How reproducible:


Steps to Reproduce:
1. use a spec file with the following lines (used to switch features on/off)
%define alpha %{nil}
%define rescue %{nil}
%define rel 7.22
%if "%{alpha}" != ""
Release: 0.%{alpha}.%{rel}%{rescue}
%else
Release: %{rel}%{rescue}

This bails out at the %if line, same happens p.e. for
%if %alpha
%if %{alpha}
%if "%{alpha}" == "%{nil}"
  
Actual results:
hagen:[RHEL-2_1] >make prep                                             
error: syntax error in expression                                       
error: vim.spec:8: parseExpressionBoolean returns -1                    
error: query of specfile vim.spec failed, can't parse                   
error: syntax error in expression                                       
error: vim.spec:8: parseExpressionBoolean returns -1                    
error: query of specfile vim.spec failed, can't parse