copy baserelease sanity check from rawhide

.gitignore

@@ -2,4 +2,5 @@ linux-*.tar.bz2
 patch-*.bz2
 clog
 *.rpm
+*.orig
 kernel-[23].*/

kernel.spec

@@ -48,8 +48,11 @@ Summary: The Linux kernel
 # reset this by hand to 1 (or to 0 and then use rpmdev-bumpspec).
 # scripts/rebase.sh should be made to do that for you, actually.
 #
-# For non-released -rc kernels, this will be prepended with "0.", so
-# for example a 3 here will become 0.3
+# NOTE: baserelease must be > 0 or bad things will happen if you switch
+#       to a released kernel (released version will be < rc version)
+#
+# For non-released -rc kernels, this will be appended after the rcX and
+# gitX tags, so a 3 here would become part of release "0.rcX.gitX.3"
 #
 %global baserelease 1
 %global fedora_build %{baserelease}
@@ -1009,6 +1012,11 @@ exit 1
 %endif
 %endif
 
+%if !%{baserelease}
+echo "baserelease must be greater than zero"
+exit 1
+%endif
+
 # more sanity checking; do it quietly
 if [ "%{patches}" != "%%{patches}" ] ; then
   for patch in %{patches} ; do