complain about b0rked ChartsRegexps

docs/Changelog

@@ -1,7 +1,8 @@
 pisg (0.67) - ??
    Christoph:
    * Features:
-     + Recognize ogg and wma suffixes in song stats.
+     + Recognize ogg and wma suffixes in song stats, complain about invalid
+       ChartsRegexp.
      + Added support for multiple channels in config with the same name.
        Even multiple channel directives for the very same channel are
        supported (closes SF tracker #967404, patch by Torbjörn Svensson).

docs/pisg-doc.xml

@@ -2968,8 +2968,9 @@
     <title>Description</title>
     <para>
     This option is a perl regexp that is used to recognize songs played. Please
-    tell the pisg mailing list if you have a better default. See also
-    <xref linkend="ShowCharts" /> and <xref linkend="ChartsHistory" />.
+    tell the pisg mailing list if you have a better default. The regexp MUST
+    contain a single () pair to extract the song name. See also the perlre(1)
+    manpage, <xref linkend="ShowCharts" /> and <xref linkend="ChartsHistory" />.
     </para>
     </refsect1>
     <refsect1>

modules/Pisg/Parser/Logfile.pm

@@ -413,14 +413,12 @@ sub _parse_file
                         $stats->{smileynicks}{$1} = $nick;
                     }
 
-                    if ($self->{cfg}->{showkarma}) {
-                        # require 2 chars (catches C++), nick must not end in [+=-]
-                        if ($saying =~ /^(\S*\w\S*\w\S*(?<![+=-]))(\+\+|==|--)$/o) {
-                            my $thing = lc $1;
-                            my $k = $2 eq "++" ? 1 : ($2 eq "==" ? 0 : -1);
-                            $stats->{karma}{$thing}{$nick} = $k
-                                if !is_ignored($thing) and $thing ne lc($nick);
-                        }
+                    # require 2 chars (catches C++), nick must not end in [+=-]
+                    if ($saying =~ /^(\S*\w\S*\w\S*(?<![+=-]))(\+\+|==|--)$/o) {
+                        my $thing = lc $1;
+                        my $k = $2 eq "++" ? 1 : ($2 eq "==" ? 0 : -1);
+                        $stats->{karma}{$thing}{$nick} = $k
+                            if !is_ignored($thing) and $thing ne lc($nick);
                     }
 
                     # Find URLs
@@ -657,6 +655,10 @@ sub _parse_words
 sub _charts
 {
     my ($self, $stats, $Song, $nick) = @_;
+    unless (defined $Song) {
+        warn "Your ChartsRegexp is b0rked. Read the manual! This happened";
+        return;
+    }
     $Song =~ s/_/ /g;
     $Song =~ s/\d+ ?- ?//;
     $Song =~ s/\.(mp3|ogg|wma)//ig;