Exit nicely, even if a VM doesn't have <routed-subnet>HEADmaster

If there is no '<routed-subnet xmlns="...">' tag, then the xmllint
call will fail, and since we are running with `set -e`, then it will
terminate the script.

Before a VM not using routed-subnet would cause the following error:

  error: Hook script execution failed: internal error: \
  Child process (LC_ALL=C PATH=<...> /etc/libvirt/hooks/qemu <vm> \
  prepare begin -) unexpected exit status 10

Signed-off-by: Asbjørn Sloth Tønnesen <ast@2e8.dk>

1 files changed, 4 insertions, 1 deletions

diff --git a/qemu b/qemu
index b4272dd..9324f63 100755
--- a/qemu
+++ b/qemu
@@ -53,7 +53,10 @@ get_config(){
 	local ns='https://2e8.dk/libvirt-routed-subnet'
 	local query = "//*[local-name()='$tag' and namespace-uri()='$ns']"
 	fullxml="$(cat "$configfile")"
-	routingxml="$(xpath "$query" "$fullxml")"
+	routingxml="$(xpath "$query" "$fullxml" || true)"
+	if [ -z "$routingxml" ] ; then
+		exit 0
+	fi
 }
 
 get_device(){