[libvirt PATCH] qemu: Avoid segfault when driver initialization fails

[Jiri Denemark <jdenemar@xxxxxxxxxx>]

In case qemuStateInitialize fails for any reason (e.g., a typo in
qemu.conf), it properly cleans up after itself and sets qemu_driver back
to NULL. A tiny bit later the daemon asks all drivers to shutdown by
calling their stateShutdown* APIs. But the implementation of these APIs
in QEMU driver expected qemu_driver to be initialized at this point
causing a segfault otherwise.

Signed-off-by: Jiri Denemark <jdenemar@xxxxxxxxxx>
---
 src/qemu/qemu_driver.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index ed966cf7e3..a68ebe5259 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -1075,6 +1075,9 @@ qemuStateStop(void)
 static int
 qemuStateShutdownPrepare(void)
 {
+    if (!qemu_driver)
+        return 0;
+
     virThreadPoolStop(qemu_driver->workerPool);
     return 0;
 }
@@ -1094,6 +1097,9 @@ qemuDomainObjStopWorkerIter(virDomainObjPtr vm,
 static int
 qemuStateShutdownWait(void)
 {
+    if (!qemu_driver)
+        return 0;
+
     virDomainObjListForEach(qemu_driver->domains, false,
                             qemuDomainObjStopWorkerIter, NULL);
     virThreadPoolDrain(qemu_driver->workerPool);
-- 
2.30.0