treat all NULL returns from virXMLNodeContentString() as an error

and stop erroneously equating NULL with "". The latter means that the
element has empty content, while the former means there was an error
during parsing (either internal with the parser, or the content of the
XML was bad).

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

src/conf/domain_conf.c

@@ -1650,7 +1650,8 @@ virDomainBlkioDeviceParseXML(xmlNodePtr root,
         if (node->type != XML_ELEMENT_NODE)
             continue;
 
-        c = virXMLNodeContentString(node);
+        if (!(c = virXMLNodeContentString(node)))
+            return -1;
 
         if (virXMLNodeNameEqual(node, "path")) {
             /* To avoid the need for explicit cleanup on failure,
@@ -9377,10 +9378,12 @@ virDomainLeaseDefParseXML(xmlNodePtr node)
     while (cur != NULL) {
         if (cur->type == XML_ELEMENT_NODE) {
             if (!key && virXMLNodeNameEqual(cur, "key")) {
-                key = virXMLNodeContentString(cur);
+                if (!(key = virXMLNodeContentString(cur)))
+                    goto error;
             } else if (!lockspace &&
                        virXMLNodeNameEqual(cur, "lockspace")) {
-                lockspace = virXMLNodeContentString(cur);
+                if (!(lockspace = virXMLNodeContentString(cur)))
+                    goto error;
             } else if (!path &&
                        virXMLNodeNameEqual(cur, "target")) {
                 path = virXMLPropString(cur, "path");
@@ -10599,16 +10602,19 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,
 
         } else if (!serial &&
                    virXMLNodeNameEqual(cur, "serial")) {
-            serial = virXMLNodeContentString(cur);
+            if (!(serial = virXMLNodeContentString(cur)))
+                goto error;
         } else if (!wwn &&
                    virXMLNodeNameEqual(cur, "wwn")) {
-            wwn = virXMLNodeContentString(cur);
+            if (!(wwn = virXMLNodeContentString(cur)))
+                goto error;
 
             if (!virValidateWWN(wwn))
                 goto error;
         } else if (!vendor &&
                    virXMLNodeNameEqual(cur, "vendor")) {
-            vendor = virXMLNodeContentString(cur);
+            if (!(vendor = virXMLNodeContentString(cur)))
+                goto error;
 
             if (strlen(vendor) > VENDOR_LEN) {
                 virReportError(VIR_ERR_XML_ERROR, "%s",
@@ -10623,7 +10629,8 @@ virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,
             }
         } else if (!product &&
                    virXMLNodeNameEqual(cur, "product")) {
-            product = virXMLNodeContentString(cur);
+            if (!(product = virXMLNodeContentString(cur)))
+                goto error;
 
             if (strlen(product) > PRODUCT_LEN) {
                 virReportError(VIR_ERR_XML_ERROR, "%s",
@@ -13529,20 +13536,16 @@ virDomainSmartcardDefParseXML(virDomainXMLOptionPtr xmlopt,
                                      "exactly three certificates"));
                     goto error;
                 }
-                def->data.cert.file[i] = virXMLNodeContentString(cur);
+                if (!(def->data.cert.file[i] = virXMLNodeContentString(cur)))
-                if (!def->data.cert.file[i]) {
-                    virReportOOMError();
                     goto error;
-                }
+
                 i++;
             } else if (cur->type == XML_ELEMENT_NODE &&
                        virXMLNodeNameEqual(cur, "database") &&
                        !def->data.cert.database) {
-                def->data.cert.database = virXMLNodeContentString(cur);
+                if (!(def->data.cert.database = virXMLNodeContentString(cur)))
-                if (!def->data.cert.database) {
-                    virReportOOMError();
                     goto error;
-                }
+
                 if (*def->data.cert.database != '/') {
                     virReportError(VIR_ERR_XML_ERROR,
                                    _("expecting absolute path: %s"),
@@ -15667,8 +15670,10 @@ virSysinfoOEMStringsParseXML(xmlNodePtr node,
         goto cleanup;
 
     def->nvalues = nstrings;
-    for (i = 0; i < nstrings; i++)
+    for (i = 0; i < nstrings; i++) {
-        def->values[i] = virXMLNodeContentString(strings[i]);
+        if (!(def->values[i] = virXMLNodeContentString(strings[i])))
+            goto cleanup;
+    }
 
     *oem = g_steal_pointer(&def);
     ret = 0;
@@ -15796,7 +15801,9 @@ virSysinfoParseFWCfgDef(virSysinfoDefPtr def,
             return -1;
         }
 
-        value = virXMLNodeContentString(nodes[i]);
+        if (!(value = virXMLNodeContentString(nodes[i])))
+            return -1;
+
         file = virXMLPropString(nodes[i], "file");
 
         if (virStringIsEmpty(value))
@@ -19904,8 +19911,10 @@ virDomainLoaderDefParseXML(xmlNodePtr node,
     if (!fwAutoSelect) {
         readonly_str = virXMLPropString(node, "readonly");
         type_str = virXMLPropString(node, "type");
-        loader->path = virXMLNodeContentString(node);
+        if (!(loader->path = virXMLNodeContentString(node)))
-        if (STREQ_NULLABLE(loader->path, ""))
+            return -1;
+
+        if (STREQ(loader->path, ""))
             VIR_FREE(loader->path);
     }
 
@@ -20129,14 +20138,15 @@ virDomainVcpuParse(virDomainDefPtr def,
     vcpus = maxvcpus = 1;
 
     if ((vcpuNode = virXPathNode("./vcpu[1]", ctxt))) {
-        if ((tmp = virXMLNodeContentString(vcpuNode))) {
+        if (!(tmp = virXMLNodeContentString(vcpuNode)))
-            if (virStrToLong_ui(tmp, NULL, 10, &maxvcpus) < 0) {
+            return -1;
-                virReportError(VIR_ERR_XML_ERROR, "%s",
+
-                               _("maximum vcpus count must be an integer"));
+        if (virStrToLong_ui(tmp, NULL, 10, &maxvcpus) < 0) {
-                return -1;
+            virReportError(VIR_ERR_XML_ERROR, "%s",
-            }
+                           _("maximum vcpus count must be an integer"));
-            VIR_FREE(tmp);
+            return -1;
         }
+        VIR_FREE(tmp);
 
         if ((tmp = virXMLPropString(vcpuNode, "current"))) {
             if (virStrToLong_ui(tmp, NULL, 10, &vcpus) < 0) {
@@ -20397,7 +20407,9 @@ virDomainDefParseBootOptions(virDomainDefPtr def,
 
             if (STREQ_NULLABLE(tmp, "slic")) {
                 VIR_FREE(tmp);
-                tmp = virXMLNodeContentString(nodes[0]);
+                if (!(tmp = virXMLNodeContentString(nodes[0])))
+                    return -1;
+
                 def->os.slic_table = virFileSanitizePath(tmp);
             } else {
                 virReportError(VIR_ERR_XML_ERROR,

src/conf/network_conf.c

@@ -722,7 +722,10 @@ virNetworkDNSHostDefParseXML(const char *networkName,
               if (cur->children != NULL) {
                   g_autofree char *name = virXMLNodeContentString(cur);
 
-                  if (!name) {
+                  if (!name)
+                      goto error;
+
+                  if (!name[0]) {
                       virReportError(VIR_ERR_XML_DETAIL,
                                      _("Missing hostname in network '%s' DNS HOST record"),
                                      networkName);

src/conf/node_device_conf.c

@@ -1986,10 +1986,12 @@ virNodeDeviceDefParseXML(xmlXPathContextPtr ctxt,
 
         switch ((virNodeDevDevnodeType)val) {
         case VIR_NODE_DEV_DEVNODE_DEV:
-            def->devnode = virXMLNodeContentString(node);
+            if (!(def->devnode = virXMLNodeContentString(node)))
+                goto error;
             break;
         case VIR_NODE_DEV_DEVNODE_LINK:
-            def->devlinks[m++] = virXMLNodeContentString(node);
+            if (!(def->devlinks[m++] = virXMLNodeContentString(node)))
+                goto error;
             break;
         case VIR_NODE_DEV_DEVNODE_LAST:
             break;