fix various warnings

* Use of uninitialized value in pattern match (m//) at C4/Biblio.pm line 1305
  (displaying MARC21 856s that don't have $3)
* Use of uninitialized value in multiplication (*) at catalogue/detail.pl line 243.
  (attemping to calculate average Amazon rating if no Amazon info
   is available)
* opac-detail.pl: Use of uninitialized value in length at C4/External/Amazon.pm line 90
  (attempting to calculate length of $isbn if it happens to be undef)

Signed-off-by: Galen Charlton <galen.charlton@liblime.com>
Signed-off-by: Henri-Damien LAURENT <henridamien.laurent@biblibre.com>

diff --git a/C4/Biblio.pm b/C4/Biblio.pm
index 8d12925..0886cb2 100755 (executable)
--- a/C4/Biblio.pm
+++ b/C4/Biblio.pm
@@ -1276,7 +1276,7 @@ sub GetMarcUrls {
                 };
                 $marcurl->{'linktext'} = $link || $s3 || C4::Context->preference('URLLinkText') || $url;
                 $marcurl->{'part'} = $s3 if ($link);
-                $marcurl->{'toc'} = 1 if ( $s3 =~ /^table/i );
+                $marcurl->{'toc'} = 1 if ( defined($s3) && $s3 =~ /^table/i );
             } else {
                 $marcurl->{'linktext'} = $field->subfield('2') || C4::Context->preference('URLLinkText') || $url;
                 $marcurl->{'MARCURL'} = $url;