fixed infinite loop for empty response in GitLab::API::Iterator

GitLab/API/Iterator.pm

@@ -148,28 +148,28 @@ sub next_block {
         return 0;
     }
 
-    if (!defined $self->{pages_total}) {
-        $self->{pages_total} = $response->header("X-Total-Pages");
-    }
+    croak "Response for " . $self->name . " did not contain an array"
+        unless ref $data eq "ARRAY";
 
-    # if there was no X-Total-Pages, the response is not paginated, blame the user
+    # get total number of pages from the header
     if (!defined $self->{pages_total}) {
         # some requests are not paginated if additional parameters are provided
-        # carp "Iterating over non-paginated request for " . $self->name;
-        $self->{pages_total} = 1;
+        # use 1 if there are data, 0 otherwise
+        my $default = @$data ? 1 : 0;
+        $self->{pages_total} = $response->header("X-Total-Pages") // $default;
+        $self->idebug("total pages $self->{pages_total}");
     }
 
-    croak "Response for " . $self->name . " did not contain an array"
-        unless ref $data eq "ARRAY";
-
     push @{$self->{data}},      @$data;
     push @{$self->{responses}}, $response;
 
-    $self->api->{last} = $response;
-    $self->{count} += scalar @$data;
-    ++$self->{pages_read};
+    $self->api->{last}  = $response;
+    $self->{count}     += scalar @$data;
+
+    # only increase read pages if there are pages to read
+    ++$self->{pages_read} if $self->{pages_total};
 
-    $self->{finished} = $self->{pages_read} == $self->{pages_total};
+    $self->{finished} = !$self->{pages_total} || $self->{pages_read} == $self->{pages_total};
     $self->idebug("block read successful");
     $self->idebug("all blocks were read") if $self->{finished};
     return 1;