Fixed the blockage of using the 'grep -n' command when xpp3 .xml does not exist

xpp3.spec

@@ -1,6 +1,6 @@
 Name:           xpp3
 Version:        1.1.4
-Release:        21
+Release:        22
 License:        ASL 1.1
 Summary:        Xml Pull Parser 3rd Edition
 URL:            http://www.extreme.indiana.edu/xgws/xsoap/xpp/mxp1/index.html
@@ -39,11 +39,13 @@ ant xpp3 junit apidoc
 jar ufm build/xpp3-1.1.4c.jar %{SOURCE4}
 %install
 ret=0
+%if 0%(find %{_buildrootdir} -name xpp3.xml)
 for line in `grep -n uuid $(find %{_buildrootdir} -name xpp3.xml) | cut -d \: -f 1`
 do
     sed -i "${line}s/[0-9a-f]\{8\}-[0-9a-f]\{4\}-[0-9a-f]\{4\}-[0-9a-f]\{4\}-[0-9a-f]\{12\}/f2f42549-cfab-4d71-be48-5e9f9a41e5f${ret}/g" $(find %{_buildrootdir} -name xpp3.xml)
     ret=`expr $ret + 1`
 done
+%endif
 %mvn_file ':{*}' @1
 %mvn_package :xpp3_min minimal
 %mvn_artifact %{SOURCE1} build/xpp3-1.1.4c.jar
@@ -58,5 +60,8 @@ done
 %files help -f .mfiles-javadoc
 
 %changelog
+* Mon Mar 13 2023 Wenlong Zhang<zhangwenlong@loongson.cn> - 1.1.4-22
+- Fixed the blockage of using the 'grep -n' command when xpp3 .xml does not exist
+
 * Tue Dec 3 2019 Ling Yang <lingyang2@huawei.com> - 1.1.4-20
 - Package init