[libvirt] [PATCH 3/3] libvirt-domain: virConnectListDomains: Return 0 on zero-size buffer

[Erik Skultety]

It doesn't make sense to pass a target buffer into an API, declaring its
size as 0 and expect some meaningful result. Since this used to work
pre-Glib era, we shouldn't end with an error, but we can return 0
for the number of domains immediately, instead of calling into the
daemon, which is exactly what the daemon would have returned anyway.

Signed-off-by: Erik Skultety <eskultet at redhat.com>
---
 src/libvirt-domain.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
index 02622cb2ca..0def40fdf7 100644
--- a/src/libvirt-domain.c
+++ b/src/libvirt-domain.c
@@ -62,6 +62,9 @@ virConnectListDomains(virConnectPtr conn, int *ids, int maxids)
     virCheckNonNullArgGoto(ids, error);
     virCheckNonNegativeArgGoto(maxids, error);
 
+    if (maxids == 0)
+        return 0;
+
     if (conn->driver->connectListDomains) {
         int ret = conn->driver->connectListDomains(conn, ids, maxids);
         if (ret < 0)
-- 
2.23.0