[PATCH] qemu: don't raise error upon interface update without <frames/> for <rx/> in coalesce

[Kristina Hanicova <khanicov@xxxxxxxxxx>]

With this, incomplete XML without <frames/> for <rx/> in coalesce
won't raise error as before. It will leave the coalesce parameter
empty, thanks to passing it as a parameter and return an integer
to indicate error state - previously it returned pointer (or NULL
for both error and incomplete XML).

The code went through some refactoring:
* change of a condition
* addition of a parameter
* change of order, that allowed removal of VIR_FREE
* removal of redundant labels and variables

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1535930
Signed-off-by: Kristina Hanicova <khanicov@xxxxxxxxxx>
---
 src/conf/domain_conf.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index b731744f04..798594f520 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -7516,11 +7516,11 @@ virDomainNetIPInfoParseXML(const char *source,
 }
 
 
-static virNetDevCoalescePtr
+static int
 virDomainNetDefCoalesceParseXML(xmlNodePtr node,
-                                xmlXPathContextPtr ctxt)
+                                xmlXPathContextPtr ctxt,
+                                virNetDevCoalescePtr *coalesce)
 {
-    virNetDevCoalescePtr ret = NULL;
     VIR_XPATH_NODE_AUTORESTORE(ctxt)
     unsigned long long tmp = 0;
     g_autofree char *str = NULL;
@@ -7529,15 +7529,13 @@ virDomainNetDefCoalesceParseXML(xmlNodePtr node,
 
     str = virXPathString("string(./rx/frames/@max)", ctxt);
     if (!str)
-        return NULL;
-
-    ret = g_new0(virNetDevCoalesce, 1);
+        return 0;
 
     if (virStrToLong_ullp(str, NULL, 10, &tmp) < 0) {
         virReportError(VIR_ERR_XML_DETAIL,
                        _("cannot parse value '%s' for coalesce parameter"),
                        str);
-        goto error;
+        return -1;
     }
 
     if (tmp > UINT32_MAX) {
@@ -7545,15 +7543,13 @@ virDomainNetDefCoalesceParseXML(xmlNodePtr node,
                        _("value '%llu' is too big for coalesce "
                          "parameter, maximum is '%lu'"),
                        tmp, (unsigned long) UINT32_MAX);
-        goto error;
+        return -1;
     }
-    ret->rx_max_coalesced_frames = tmp;
 
-    return ret;
+    *coalesce = g_new0(virNetDevCoalesce, 1);
+    (*coalesce)->rx_max_coalesced_frames = tmp;
 
- error:
-    VIR_FREE(ret);
-    return NULL;
+    return 0;
 }
 
 static void
@@ -11517,8 +11513,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
 
     node = virXPathNode("./coalesce", ctxt);
     if (node) {
-        def->coalesce = virDomainNetDefCoalesceParseXML(node, ctxt);
-        if (!def->coalesce)
+        if (virDomainNetDefCoalesceParseXML(node, ctxt, &def->coalesce) < 0)
             goto error;
     }
 
-- 
2.29.2