[COMMITTED] db: fix rec_db_set crash with empty databases

[Jose E. Marchesi]

2022-04-25  Jose E. Marchesi  <jemarch@gnu.org>

        * src/rec-db.c (rec_db_set): Avoid segfault with databases with no
        record sets.
        * torture/utils/recset.sh: New test.
---
 ChangeLog               | 6 ++++++
 src/rec-db.c            | 2 +-
 torture/utils/recset.sh | 8 ++++++++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index eb79621..5527ba2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2022-04-25  Jose E. Marchesi  <jemarch@gnu.org>
+
+       * src/rec-db.c (rec_db_set): Avoid segfault with databases with no
+       record sets.
+       * torture/utils/recset.sh: New test.
+
 2022-04-16  Jose E. Marchesi  <jemarch@gnu.org>
 
        * configure.ac: Bump version to 1.9.
diff --git a/src/rec-db.c b/src/rec-db.c
index 1d91441..e90a734 100644
--- a/src/rec-db.c
+++ b/src/rec-db.c
@@ -1431,7 +1431,7 @@ bool rec_db_set (rec_db_t    db,
       rset = rec_db_get_rset (db, 0);
 
   /* Don't process empty record sets.  */
-  if (rec_rset_num_records (rset) == 0)
+  if (!rset || rec_rset_num_records (rset) == 0)
     return true;
 
   /* If the user requested to manipulate random records then calculate
diff --git a/torture/utils/recset.sh b/torture/utils/recset.sh
index f44ee59..d73d530 100755
--- a/torture/utils/recset.sh
+++ b/torture/utils/recset.sh
@@ -98,10 +98,18 @@ field2: value32
 field3: value33
 '
 
+test_declare_input_file empty ''
+
 #
 # Declare tests.
 #
 
+test_tool recset-empty ok \
+          recset \
+          '' \
+          empty \
+          ''
+
 test_tool recset-append-field ok \
           recset \
           '-n 0 -f foo -a bar' \
-- 
2.11.0