From 0e82fa4c345acb7ad52e0da0e54f7375eda57657 Mon Sep 17 00:00:00 2001
From: Michal Privoznik <mprivozn@redhat.com>
Date: Tue, 25 Oct 2016 12:16:36 +0200
Subject: [PATCH] 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>
---
 src/qemu/qemu_hotplug.c | 4 ++++
 1 file changed, 4 insertions(+)

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;
 }
 
-- 
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