From: Michal Privoznik <mprivozn@redhat.com>
Date: Tue, 25 Oct 2016 10:16:36 +0000 (+0200)
Subject: qemuDomainAttachNetDevice: Don't overwrite error on rollback
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=0e82fa4c34;p=libvirt.git

qemuDomainAttachNetDevice: Don't overwrite error on rollback

If there is an error hotpluging a net device (for whatever
reason) a rollback operation is performed. However, whilst doing
so various helper functions that are called report errors on
their own. This results in the original error to be overwritten
and thus misleading the user.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 67e6ec34a8..61ab4440a5 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -935,6 +935,7 @@ qemuDomainAttachNetDevice(virQEMUDriverPtr driver,
                           virDomainNetDefPtr net)
 {
     qemuDomainObjPrivatePtr priv = vm->privateData;
+    virErrorPtr originalError = NULL;
     char **tapfdName = NULL;
     int *tapfd = NULL;
     size_t tapfdSize = 0;
@@ -1320,6 +1321,7 @@ qemuDomainAttachNetDevice(virQEMUDriverPtr driver,
     if (!virDomainObjIsActive(vm))
         goto cleanup;
 
+    originalError = virSaveLastError();
     if (vlan < 0) {
         if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_NETDEV)) {
             char *netdev_name;
@@ -1350,6 +1352,8 @@ qemuDomainAttachNetDevice(virQEMUDriverPtr driver,
         ignore_value(qemuDomainObjExitMonitor(driver, vm));
         VIR_FREE(hostnet_name);
     }
+    virSetError(originalError);
+    virFreeError(originalError);
     goto cleanup;
 }