don't crash as easily with bad slave settings

(tomas doran)

git-svn-id: http://code.sixapart.com/svn/mogilefs/trunk@1457 f67b2e87-0811-0410-a7e0-dd94e48410d6

CHANGES

@@ -1,3 +1,6 @@
+        * make it slightly harder to crash trackers with bad slave DB settings
+          (Tomas Doran)
+
         * make tracker -> storage node connection timeout configurable.
           was hardcoded to 2 seconds. (Tomas Doran)
 

lib/MogileFS/Store.pm

@@ -2,7 +2,7 @@ package MogileFS::Store;
 use strict;
 use warnings;
 use Carp qw(croak);
-use MogileFS::Util qw(throw max);
+use MogileFS::Util qw(throw max error);
 use DBI;  # no reason a Store has to be DBI-based, but for now they all are.
 use List::Util ();
 
@@ -186,8 +186,18 @@ sub _slaves_list {
     my @ret;
     foreach my $key (split /\s*,\s*/, $sk) {
         my $slave = MogileFS::Config->server_setting("slave_$key");
+
+        if (!$slave) {
+            error("key for slave DB config: slave_$key not found in configuration");
+            next;
+        }
+
         my ($dsn, $user, $pass) = split /\|/, $slave;
-        push @ret, [$dsn, $user, $pass];
+        if (!defined($dsn) or !defined($user) or !defined($pass)) {
+            error("key slave_$key contains $slave, which doesn't split in | into DSN|user|pass - ignoring");
+            next;
+        }
+        push @ret, [$dsn, $user, $pass]
     }
 
     $self->{slave_list_cache}     = \@ret;