Fix for http://rpm5.org/cvs/tktview?tn=41

--- rpm-5.4.10/macros/macros.rpmbuild.in~	2012-07-06 17:39:16.000000000 +0200
+++ rpm-5.4.10/macros/macros.rpmbuild.in	2012-09-15 20:15:30.455784728 +0200
@@ -169,7 +169,7 @@
 %define __patch_suffix  %{-b:-b --suffix %{-b*}} %{-z:--suffix %{-z*}} \
 %define __patch_fuzz    %{?_default_patch_fuzz:%(test %{_default_patch_fuzz} -ge 0 && echo "--fuzz=%{_default_patch_fuzz} ")} \
 %define __patch_options %{_default_patch_flags} %{-p:-p%{-p*}} %{-F:-F%{-F*}} %{-d:-d%{-d*}} %{-R} %{-E} %{__patch_suffix} \
-echo "Patch #%{__patch_number} (%{basename:%{__patch_file}}):" && ( %{uncompress:%{__patch_file}} | %{__patch} %{__patch_fuzz}%{__patch_options} ) || exit 1\
+echo "Patch #%{__patch_number} (%{basename:%{__patch_file}}):" && [ -f %{__patch_file} ] && %{uncompress:%{__patch_file}} | %{__patch} %{__patch_fuzz}%{__patch_options} || exit 1\
 }
 
 #