Fix port value parsing for serial and parallel ports

this is the patch to fix the virDomainChrDefParseTargetXML() functionality
to parse the target port from XML if available. This is necessary for
multiple serial port support which is the second part of this patch.
Signed-off-by: NMichal Novotny <minovotn@redhat.com>

src/conf/domain_conf.c

@@ -2974,7 +2974,8 @@ virDomainChrDefParseTargetXML(virCapsPtr caps,
     default:
         portStr = virXMLPropString(cur, "port");
         if (portStr == NULL) {
-            /* Not required. It will be assigned automatically later */
+            /* Set to negative value to indicate we should set it later */
+            def->target.port = -1;
             break;
         }
 
@@ -2984,6 +2985,7 @@ virDomainChrDefParseTargetXML(virCapsPtr caps,
                                  portStr);
             goto error;
         }
+        def->target.port = port;
         break;
     }
 
@@ -5547,7 +5549,15 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
         if (!chr)
             goto error;
 
-        chr->target.port = i;
+        if (chr->target.port == -1) {
+            int maxport = -1;
+            int j;
+            for (j = 0 ; j < i ; j++) {
+                if (def->parallels[j]->target.port > maxport)
+                    maxport = def->parallels[j]->target.port;
+            }
+            chr->target.port = maxport + 1;
+        }
         def->parallels[def->nparallels++] = chr;
     }
     VIR_FREE(nodes);
@@ -5567,7 +5577,15 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
         if (!chr)
             goto error;
 
-        chr->target.port = i;
+        if (chr->target.port == -1) {
+            int maxport = -1;
+            int j;
+            for (j = 0 ; j < i ; j++) {
+                if (def->serials[j]->target.port > maxport)
+                    maxport = def->serials[j]->target.port;
+            }
+            chr->target.port = maxport + 1;
+        }
         def->serials[def->nserials++] = chr;
     }
     VIR_FREE(nodes);