better support for ISIS files with null pointers (it will warn and not die)

[Biblio-Isis] / lib / Biblio / Isis.pm

diff --git a/lib/Biblio/Isis.pm b/lib/Biblio/Isis.pm
index ea1c64f..ba32c69 100644 (file)
--- a/lib/Biblio/Isis.pm
+++ b/lib/Biblio/Isis.pm
@@ -9,7 +9,7 @@ use Data::Dumper;
 BEGIN {
        use Exporter ();
        use vars qw ($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
-       $VERSION     = 0.12;
+       $VERSION     = 0.13;
        @ISA         = qw (Exporter);
        #Give a hoot don't pollute, do not export more than needed by default
        @EXPORT      = qw ();
@@ -264,7 +264,15 @@ sub fetch {
 
        # read XRFMFB abd XRFMFP
        read($self->{'fileXRF'}, $buff, 4);
-       my $pointer=unpack("V",$buff) || croak "pointer is null";
+       my $pointer=unpack("V",$buff);
+       if (! $pointer) {
+               if ($self->{include_deleted}) {
+                       return;
+               } else {
+                       warn "pointer for MFN $mfn is null\n";
+                       return;
+               }
+       }
 
        # check for logically deleted record
        if ($pointer & 0x80000000) {
@@ -393,7 +401,7 @@ sub to_ascii {
 
        my $mfn = shift || croak "need MFN";
 
-       my $rec = $self->fetch($mfn);
+       my $rec = $self->fetch($mfn) || return;
 
        my $out = "0\t$mfn";
 
@@ -461,7 +469,7 @@ sub to_hash {
        # init record to include MFN as field 000
        my $rec = { '000' => [ $mfn ] };
 
-       my $row = $self->fetch($mfn);
+       my $row = $self->fetch($mfn) || return;
 
        foreach my $k (keys %{$row}) {
                foreach my $l (@{$row->{$k}}) {