check that matrix replace method is not used with a Formula

Author: Alex-Jordan

lib/Value/Matrix.pm

@@ -1368,20 +1368,22 @@ Usage:
 sub replace {
 	my ($self, $value, @indices) = @_;
 	$value = Value::makeValue($value) unless Value::isValue($value);
+	$self->Error('Cannot replace a matrix entry with a Formula') if Value::isFormula($value);
 	my $dim = $self->degree;
 	@indices = @{ $indices[0] } if (ref $indices[0] eq 'ARRAY');
 	$self->Error("There should be $dim indices") unless $dim == @indices;
 	my $data = $self->{data};
 	my $i    = pop(@indices) - 1;
+
 	for (my $n = 0; @indices; $n++) {
 		my $j = shift(@indices) - 1;
-		$self->Error("The " . $self->NameForNumber($n + 1) . " index is outside of the array bounds")
+		$self->Error('The ' . $self->NameForNumber($n + 1) . ' index is outside of the array bounds')
 			if $j < 0 || $j >= scalar(@$data);
 		$data = $data->[$j]->{data};
 	}
-	$self->Error("The last index is outside of the array bounds")
+	$self->Error('The last index is outside of the array bounds')
 		if $i < 0 || $i >= scalar(@$data);
-	$self->Error("The new entry value should be " . $data->[$i]->showType . " not " . $value->showType)
+	$self->Error('The new entry value should be ' . $data->[$i]->showType . ' not ' . $value->showType)
 		unless $value->type eq $data->[$i]->type;
 	my $old = $data->[$i];
 	$data->[$i] = $value;

t/math_objects/matrix.t

@@ -240,6 +240,9 @@ subtest 'Replace a value' => sub {
 	like dies {
 		$B->replace(Point(1, 2), [ 2, 1 ]);
 	}, qr/The new entry value should be a Number not a Point/, 'Check replaced value has the same type';
+	like dies {
+		$B->replace(Formula('x'), [ 2, 1 ]);
+	}, qr/Cannot replace a matrix entry with a Formula/, 'Check replaced value is not a Formula';
 
 };