!270 support _disable_auto_rebuilddb macro in posttrans

From: @renxichen 
Reviewed-by: @xujing99 
Signed-off-by: @xujing99

rpm.spec

@@ -1,6 +1,6 @@
 Name:          rpm
 Version:       4.18.1
-Release:       7
+Release:       8
 Summary:       RPM Package Manager
 License:       GPLv2+
 URL:           http://www.rpm.org/
@@ -217,12 +217,15 @@ make clean
 %posttrans
 {
     set -e
-    dbpath=$(rpm -E %{_dbpath})
-    while [ -e ${dbpath}/Packages ]
-    do
-       date >> /var/log/rebuilddb.log 2>&1
-       rpm -vvv --rebuilddb >> /var/log/rebuilddb.log 2>&1
-    done
+    disable_auto_rebuilddb=$(rpm -E 0%%{?_disable_auto_rebuilddb})
+    if [ ${disable_auto_rebuilddb} -eq 0 ]; then
+        dbpath=$(rpm -E %{_dbpath})
+        while [ -e ${dbpath}/Packages ]
+        do
+            date >> /var/log/rebuilddb.log 2>&1
+            rpm -vvv --rebuilddb >> /var/log/rebuilddb.log 2>&1
+        done
+    fi
 } &
 
 %files -f %{name}.lang
@@ -324,6 +327,9 @@ make clean
 %exclude %{_mandir}/man8/rpmspec.8.gz
 
 %changelog
+* Fri Sep 08 2023 renhongxun<renhongxun@h-partners.com> - 4.18.1-8
+- support _disable_auto_rebuilddb macro in posttrans
+
 * Wed Sep 06 2023 renhongxun<renhongxun@h-partners.com> - 4.18.1-7
 - Fix a copy-paste error in --help