From 1ab581366e56f9e8c9e9f2ae2a78371a79ffc23a Mon Sep 17 00:00:00 2001
From: Glenn Rice <grice1@missouriwestern.edu>
Date: Mon, 19 Feb 2024 20:06:27 -0600
Subject: [PATCH] Fix Value::Error calls in a checker for a RadioMultiAnswer
 object.

This fixes the issue observed in
https://webwork.maa.org/moodle/mod/forum/discuss.php?d=8489.  See the
problem posted there for a problem to test this with. There were two
problems really that caused the issue.  First `$self->{ans}` is a doubly
nested array.  So `$self->{ans}[0]` won't be an answer evaluator, but
rather an array of answer evaluators.  That should have been
`$self->{ans}[0][0]`.  However, that still won't work in this case,
because for the problem in that forum post there are no answers in the
first part.  Thus the `$self->{ans}[0]` is the emtpy array, and so
`$self->{ans}[0][0]` is undefined, and still not an answer evaluator.
So another approach was taken, and the context error is just added via
the RadioMultiAnswer `appendMessage` instead.

This also adds the context swapping added for MultiAnswer objects in
pull request #632.  The same issues that led to that pull request can
occur for a RadioMultiAnswer.

Furthermore, this fixes an issue in the changes from #632.  That is that
the `$ans` used on line 307 of parserMultiAnswer.pl is a variable that
is not declared. There is no error for this because `strict` is not
(yet) in effect for this macro.
---
 macros/parsers/parserMultiAnswer.pl      | 10 +++++-----
 macros/parsers/parserRadioMultiAnswer.pl | 14 ++++++++++++--
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/macros/parsers/parserMultiAnswer.pl b/macros/parsers/parserMultiAnswer.pl
index c4c2821871..d7eaaee99f 100644
--- a/macros/parsers/parserMultiAnswer.pl
+++ b/macros/parsers/parserMultiAnswer.pl
@@ -303,12 +303,12 @@ sub perform_check {
 	$rh_ans->{isPreview} = $inputs->{previewAnswers}
 		|| ($inputs_{action} && $inputs->{action} =~ m/^Preview/);
 
-	Parser::Context->current(undef, $context);                                 # change to multi-answer's context
-	my $flags = Value::contextSet($context, $self->cmp_contextFlags($ans));    # save old context flags
-	$context->{answerHash} = $rh_ans;                                          # attach the answerHash
+	Parser::Context->current(undef, $context);                                    # change to multi-answer's context
+	my $flags = Value::contextSet($context, $self->cmp_contextFlags($rh_ans));    # save old context flags
+	$context->{answerHash} = $rh_ans;                                             # attach the answerHash
 	my @result = Value::cmp_compare([@correct], [@student], $self, $rh_ans);
-	Value::contextSet($context, %{$flags});                                    # restore context values
-	$context->{answerHash} = undef;                                            # remove answerHash
+	Value::contextSet($context, %{$flags});                                       # restore context values
+	$context->{answerHash} = undef;                                               # remove answerHash
 	if (!@result && $context->{error}{flag}) { $self->cmp_error($self->{ans}[0]); return 1 }
 
 	my $result = (scalar(@result) > 1 ? [@result] : $result[0] || 0);
diff --git a/macros/parsers/parserRadioMultiAnswer.pl b/macros/parsers/parserRadioMultiAnswer.pl
index 001f890f11..d456e12bcc 100644
--- a/macros/parsers/parserRadioMultiAnswer.pl
+++ b/macros/parsers/parserRadioMultiAnswer.pl
@@ -533,7 +533,8 @@ sub check_string {
 # supplied checker.
 sub perform_check {
 	my ($self, $rh_ans) = @_;
-	$self->context->clearError;
+	my $context = $self->context;
+	$context->clearError;
 	my @correct;
 	my @student;
 	# The answers for all parts are sent to the grader.  The answers in the incorrect parts from
@@ -565,8 +566,17 @@ sub perform_check {
 	$rh_ans->{isPreview} = $main::inputs_ref->{previewAnswers}
 		|| ($main::inputs_ref->{action} && $main::inputs_ref->{action} =~ m/^Preview/);
 	$self->{errorMessages} = [];
+
+	Parser::Context->current(undef, $context);    # change to the radio multi answers's context
+	my $flags  = Value::contextSet($context, $self->cmp_contextFlags($rh_ans));    # save old context flags
 	my $result = Value::cmp_compare([@correct], [@student], $self, $rh_ans);
-	if (!defined $result && $self->context->{error}{flag}) { $self->cmp_error($self->{ans}[0]); return 1; }
+	Value::contextSet($context, %{$flags});                                        # restore context values
+	$context->{answerHash} = undef;                                                # remove answerHash
+
+	if (!defined $result && $self->context->{error}{flag}) {
+		$self->appendMessage($self->context->{error}{message});
+		return 1;
+	}
 	if (Value::matchNumber($result)) {
 		$rh_ans->score($result);
 	} else {