--- loncom/homework/grades.pm	2011/01/23 01:04:21	1.643
+++ loncom/homework/grades.pm	2011/02/07 00:53:10	1.644
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # The LON-CAPA Grading handler
 #
-# $Id: grades.pm,v 1.643 2011/01/23 01:04:21 www Exp $
+# $Id: grades.pm,v 1.644 2011/02/07 00:53:10 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -8841,7 +8841,7 @@ sub process_clicker_file {
     if ($env{'form.gradingmechanism'} eq 'given') {
         $env{'form.givenanswer'}=~s/^\s*//gs;
         $env{'form.givenanswer'}=~s/\s*$//gs;
-        $env{'form.givenanswer'}=~s/[^a-zA-Z0-9\.\*\-]+/\,/g;
+        $env{'form.givenanswer'}=~s/[^a-zA-Z0-9\.\*\-\+]+/\,/g;
         $env{'form.givenanswer'}=uc($env{'form.givenanswer'});
         my @answers=split(/\,/,$env{'form.givenanswer'});
         $foundgiven=$#answers+1;
@@ -9019,6 +9019,7 @@ sub iclicker_eval {
 	    $id=~s/^[\#0]+//;
 	    for (my $i=0;$i<$number;$i++) {
 		my $idx=3+$i*6;
+                $entries[$idx]=~s/[^a-zA-Z0-9\.\*\-\+]+//g;
 		push(@idresponses,$entries[$idx]);
 	    }
 	    $$responses{$id}=join(',',@idresponses);
@@ -9090,20 +9091,20 @@ sub assign_clicker_grades {
                     $result.='<br /><span class="LC_warning">'.
                              &mt('More than one correct result given for question "[_1]": [_2] versus [_3].',
                                  $env{'form.question:'.$i},$correct[$i],$input[$i]).'</span>';
-                 } elsif ($input[$i]) {
+                 } elsif (($input[$i]) || ($input[$i] eq '0')) {
                     $correct[$i]=$input[$i];
                  }
              }
           }
        }
        for (my $i=0;$i<$number;$i++) {
-          if (!$correct[$i]) {
+          if ((!$correct[$i]) && ($correct[$i] ne '0')) {
              $result.='<br /><span class="LC_error">'.
                       &mt('No correct result given for question "[_1]"!',
                           $env{'form.question:'.$i}).'</span>';
           }
        }
-       $result.='<br />'.&mt("Correct answer: [_1]",join(', ',map { ($_?$_:'-') } @correct));
+       $result.='<br />'.&mt("Correct answer: [_1]",join(', ',map { ((($_) || ($_ eq '0'))?$_:'-') } @correct));
     }
 # Start grading
     my $pcorrect=$env{'form.pcorrect'};
@@ -9136,17 +9137,29 @@ sub assign_clicker_grades {
           for (my $i=0;$i<$number;$i++) {
              if  ($correct[$i] eq '-') {
                 $realnumber--;
-             } elsif ($answer[$i]) {
+             } elsif (($answer[$i]) || ($answer[$i]=~/^[0\.]+$/))  {
                 if ($gradingmechanism eq 'attendance') {
                    $sum+=$pcorrect;
                 } elsif ($correct[$i] eq '*') {
                    $sum+=$pcorrect;
                 } else {
-                   if ($answer[$i] eq $correct[$i]) {
-                      $sum+=$pcorrect;
-                   } else {
-                      $sum+=$pincorrect;
+# We actually grade if correct or not
+                   my $increment=$pincorrect;
+# Special case: numerical answer "0"
+                   if ($correct[$i] eq '0') {
+                      if ($answer[$i]=~/^[0\.]+$/) {
+                         $increment=$pcorrect;
+                      }
+# General numerical answer, both evaluate to something non-zero
+                   } elsif ((1.0*$correct[$i]!=0) && (1.0*$answer[$i]!=0)) {
+                      if (1.0*$correct[$i]==1.0*$answer[$i]) {
+                         $increment=$pcorrect;
+                      }
+# Must be just alphanumeric
+                   } elsif ($answer[$i] eq $correct[$i]) {
+                      $increment=$pcorrect;
                    }
+                   $sum+=$increment;
                 }
              }
           }