Merge pull request #262 from muffato/master

Do not call fetchrow_hashref() if the statement has been exhausted

modules/Bio/EnsEMBL/Utils/SqlHelper.pm

@@ -948,6 +948,7 @@ sub _execute {
   my $sth_processor;
   if($use_hashrefs) {
     $sth_processor = sub {
+      return unless $sth->{Active};
       while( my $row = $sth->fetchrow_hashref() ) {
         my $v = $callback->($row, $sth);
         return $v if $has_return;
@@ -958,6 +959,7 @@ sub _execute {
   }
   else {
     $sth_processor = sub {
+      return unless $sth->{Active};
       while( my $row = $sth->fetchrow_arrayref() ) {
         my $v = $callback->($row, $sth);
         return $v if $has_return;

modules/t/sqlHelper.t

@@ -152,6 +152,17 @@ my $null_count_hash = $helper->execute_into_hash(
 
 ok(!exists $null_count_hash->{1}, 'Checking hash doesnt contain key for NULL value');
 
+my $iterator = $helper->execute(
+  -SQL => 'SELECT 1',
+  -ITERATOR => 1,
+);
+
+ok($iterator->has_next, 'The iterator is not empty');
+ok($iterator->has_next, 'The iterator is still not empty');
+is_deeply($iterator->to_arrayref, [[1]], 'The iterator returns all the data');
+ok(!$iterator->has_next, 'The iterator is now empty');
+ok(!$iterator->has_next, 'The iterator is still empty');
+
 ##### CHECKING WORKING WITH A STH DIRECTLY
 {
   my $v = $helper->execute_with_sth(-SQL => 'select count(*) from meta', -CALLBACK => sub {