[FIXED JENKINS-5784]

Applied the change from Olav Reinert.

changelog.html

@@ -55,6 +55,9 @@ Upcoming changes</a>
 <!-- Record your changes in the trunk here. -->
 <div id="trunk" style="display:none"><!--=TRUNK-BEGIN=-->
 <ul class=image>
+  <li class=bug>
+    Fixed a log rotation portability problem on RedHat RPM package.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-5784">issue 5784</a>)  
   <li class=bug>
     Computer.getHostName() returns null when it is not.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-13185">issue 13185</a>)  

rpm/SOURCES/jenkins.logrotate

@@ -8,6 +8,9 @@
     missingok
     create 644
     postrotate
-     kill -s SIGALRM `cat /var/run/jenkins.pid`
+      if [ -s /var/run/jenkins.pid ]; then
+        JPID=`cat /var/run/jenkins.pid`
+        test -n "`find /proc/$JPID -maxdepth 0 -user jenkins 2>/dev/null`" && /bin/kill -s ALRM $JPID || :
+      fi
     endscript
 }