[libvirt] [RFC][PATCH] change the meaning of vnc port in xml

[Hu Tao]

Now the vnc port in xml file reflects the REAL port hypervisor will
listen on for vnc connection. But vnc ports usually start from 5900,
it's common to say 0 for 5900, 1 for 5901, and so on.

This patch forbids negative vnc port number in xml, and maps port
number below 5900 to 5900+port, but no change to those greater than
5900.
---

I have no idea whether this behaviour is sane or not. But my vnc
client(vinagre) has the same behaviour, i.e., treats port 0 as 5900,
1 as 5901, but 5900 as 5900, 5901 as 5901.

 src/conf/domain_conf.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 0cea8eb..b3cbc34 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -6423,6 +6423,12 @@ virDomainGraphicsDefParseXML(xmlNodePtr node,
                 if (flags & VIR_DOMAIN_XML_INACTIVE)
                     def->data.vnc.port = 0;
                 def->data.vnc.autoport = 1;
+            } else if (def->data.vnc.port < 0) {
+                virReportError(VIR_ERR_XML_ERROR,
+                               _("invalid vnc port %s"), port);
+                goto error;
+            } else if (def->data.vnc.port < 5900) {
+                def->data.vnc.port += 5900;
             }
         } else {
             def->data.vnc.port = 0;
-- 
1.7.10.2