[WWcvs] pg: Fixed a problem introduced in the previous version where an error is reported about undefined values used in addition.

[dpvc v. a. <we...@ma...>]

Log Message:
-----------
Fixed a problem introduced in the previous version where an error is
reported about undefined values used in addition.

Modified Files:
--------------
    pg/macros:
        contextLimitedPolynomial.pl

Revision Data
-------------
Index: contextLimitedPolynomial.pl
===================================================================
RCS file: /webwork/cvs/system/pg/macros/contextLimitedPolynomial.pl,v
retrieving revision 1.19
retrieving revision 1.20
diff -Lmacros/contextLimitedPolynomial.pl -Lmacros/contextLimitedPolynomial.pl -u -r1.19 -r1.20
--- macros/contextLimitedPolynomial.pl
+++ macros/contextLimitedPolynomial.pl
@@ -150,7 +150,8 @@
     $self->{exponents} = [(0) x scalar(keys %{$vIndex})];
     $self->{exponents}[$self->{index}] = 1;
   } elsif ($self->class eq 'Number') {
-    $self->{exponents} = [];
+    my $vIndex = LimitedPolynomial::getVarIndex($self);
+    $self->{exponents} = [(0) x scalar(keys %{$vIndex})];
   }
   if ($self->{exponents}) {
     my $power = join(',',@{$self->{exponents}});