Bug 589366

Description of problem:

When a client without a reverse DNS entry is connected to the MySQL server, mytop displays an error message and doesn't show the client address.

Version-Release number of selected component (if applicable):
mytop-1.7-1.b737f60.fc12.noarch

How reproducible:
Always

Steps to Reproduce:
1. Run mytop while a client without a reverse DNS entry is connection to the MySQL server.
  
Actual results:

The following message shows up in the middle of the output:
Use of uninitialized value $host in substitution (s///) at /usr/bin/mytop line 958.

The IP address of the client is replaced by an empty string.

Expected results:

The IP address of the client should be shown.

Additional info:

Here is a patch that fixes that problem.

--- /usr/bin/mytop      2010-03-27 14:05:52.000000000 -0700
+++ /home/andreasg/bin/mytop    2010-05-05 15:15:54.000000000 -0700
@@ -955,8 +955,11 @@
         {
             $thread->{Host} =~ s/:\d+$//;
             my $host = gethostbyaddr(inet_aton($thread->{Host}), AF_INET);
-            $host =~ s/^([^.]+).*/$1/;
-            $thread->{Host} = $host;
+           if (defined $host)
+           {
+               $host =~ s/^([^.]+).*/$1/;
+               $thread->{Host} = $host;
+           }
         }
 
         ## Fix possible undefs