zip-reader: Make the zip_reader reference counted.

[pspp] / src / output / output-item.c

diff --git a/src/output/output-item.c b/src/output/output-item.c
index 9febcfabd5ba9cf8166d44276207754a27a6fde7..1b7b4b7d1c06c90714fce02a49ec45e6f70680e5 100644 (file)
--- a/src/output/output-item.c
+++ b/src/output/output-item.c
@@ -45,6 +45,7 @@ struct output_item *
 output_item_ref (const struct output_item *item_)
 {
   struct output_item *item = CONST_CAST (struct output_item *, item_);
+  assert (item->ref_cnt > 0);
   item->ref_cnt++;
   return item;
 }