[WWcvs] pg: Fixed bug where str_cmp("0") was changing the correct answer to "",

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

Log Message:
-----------
Fixed bug where str_cmp("0") was changing the correct answer to "",
making it impossible to get correct.

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

Revision Data
-------------
Index: PGanswermacros.pl
===================================================================
RCS file: /webwork/cvs/system/pg/macros/PGanswermacros.pl,v
retrieving revision 1.37
retrieving revision 1.38
diff -Lmacros/PGanswermacros.pl -Lmacros/PGanswermacros.pl -u -r1.37 -r1.38
--- macros/PGanswermacros.pl
+++ macros/PGanswermacros.pl
@@ -2844,7 +2844,7 @@
 	my $answer_evaluator = new AnswerEvaluator;
 	$answer_evaluator->{debug} = $str_params{debug};
 	$answer_evaluator->ans_hash( 	
-		correct_ans       => $str_params{correct_ans}||'',
+		correct_ans       => "$str_params{correct_ans}",
 		type              => $str_params{type}||'str_cmp',
 		score             => 0,