json_pack: Enable more complete stealing of references.

Users of the "o" format have an expectation that the object reference
will be stolen.  Any error causes the collection process to end early.
This patch causes json_pack and related functions to continue scanning
the format and parameters so all references can be stolen to prevent
leaks.  This makes no attempt to continue processing if the format
string is broken or missing.

'make check' still passes.  Ran test_pack under valgrind and verified
that the leaked reference is fixed. Added a test which uses refcounts
to verify that the reference was correctly stolen after a NULL value
error.

Issue #135

1 files changed, 9 insertions, 0 deletions

diff --git a/test/suites/api/test_pack.c b/test/suites/api/test_pack.c
index 02631a0..fa44b8b 100644
--- a/test/suites/api/test_pack.c
+++ b/test/suites/api/test_pack.c
@@ -352,6 +352,15 @@ static void run_tests()
         fail("json_pack failed to catch NULL key");
     check_error(json_error_null_value, "NULL string argument", "<args>", 1, 2, 2);
 
+    /* NULL value followed by object still steals the object's ref */
+    value = json_incref(json_object());
+    if(json_pack_ex(&error, 0, "{s:s,s:o}", "badnull", NULL, "dontleak", value))
+        fail("json_pack failed to catch NULL value");
+    check_error(json_error_null_value, "NULL string argument", "<args>", 1, 4, 4);
+    if(value->refcount != (size_t)1)
+        fail("json_pack failed to steal reference after error.");
+    json_decref(value);
+
     /* More complicated checks for row/columns */
     if(json_pack_ex(&error, 0, "{ {}: s }", "foo"))
         fail("json_pack failed to catch object as key");