--- cvs-head/lib/WAIT/InvertedIndex.pm	2000/11/11 16:58:53	22
+++ cvs-head/lib/WAIT/InvertedIndex.pm	2000/11/12 01:23:47	30
@@ -16,7 +16,9 @@
 use Fcntl;
 use WAIT::Filter;
 use Carp;
-use vars qw(%FUNC);
+use vars qw(%FUNC $VERSION);
+
+$VERSION = "1.801"; # others test if we are loaded by checking $VERSION
 
 # The dictionary has three different key types:
 #  'o'.$word
@@ -247,6 +249,12 @@
   # inverse document frequence gives the score for a term.  This sort
   # order can be exploited for tuning of single term queries.
 
+  for my $did (keys %$post) { # sanity check
+    unless ($self->{db}->{"m". $did}) {
+      warn "Warning from WAIT: DIVZERO threat from did[$did] post[$post->{$did}]";
+      $self->{db}->{"m". $did} = 1; # fails if we have not opened for writing
+    }
+  }
   for my $did (sort {    $post->{$b} / $self->{db}->{'m'. $b}
                                       <=>
                          $post->{$a} / $self->{db}->{'m'. $a}
@@ -274,6 +282,12 @@
 
   grep $occ{$_}++, &{$self->{func}}(@_);
 
+  # Be prepared for "Odd number of elements in hash assignment"
+  local $SIG{__WARN__} = sub {
+    my $warning = shift;
+    chomp $warning;
+    warn "Catching warning[$warning] during delete of key[$key]";
+  };
   for (keys %occ) {# may reorder posting list
     my %post = unpack 'w*', $db->{'p'.$_};
     delete $post{$key};
@@ -467,7 +481,14 @@
     }
 
     for (my $i=1; $i<@res; $i+=2) {
-      $res[$i] /= $self->{db}->{'m'. $res[$i-1]} / $idf;
+      # $res[$i] /= $self->{db}->{'m'. $res[$i-1]} / $idf;
+      # above was written badly, allows two DIV_ZERO problems.
+      my $maxtf = $self->{db}->{"m". $res[$i-1]};
+      unless ($maxtf) {
+        warn "WAIT-Warning: Averting DIVZERO for i[$i] \$res[\$i-1][$res[$i-1]] term[$term]";
+        $maxtf = 1;
+      }
+      $res[$i] = ($res[$i] / $maxtf) * $idf;
     }
 
     return @res
@@ -671,6 +692,7 @@
   if ($self->{mode} & O_RDWR) {
     print STDERR "Flushing $self->{cached} postings\n" if $self->{cached};
     while (my($key, $value) = each %{$self->{cache}}) {
+      $self->{db}->{"p". $key} ||= "";
       if ($self->{reorg}) {
         $self->{db}->{'p'.$key} = $self->sort_postings($self->{db}->{'p'.$key}
                                                    . $value);