[libvirt] [PATCH 4/7] virsh-interface: Resolve Coverity issues

[John Ferlan]

Recent changes uncovered FORWARD_NULL and NEGATIVE_RETURNS problems with
the processing of the 'nActiveIfaces' and 'nInactiveIfaces' and their
associated allocated arrays in 'vshInterfaceListCollect' due to the
possibility of returning -1 in a call and using the return value as a
for loop index end condition.
---
 tools/virsh-interface.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/tools/virsh-interface.c b/tools/virsh-interface.c
index 9fdd36e..5ee16a3 100644
--- a/tools/virsh-interface.c
+++ b/tools/virsh-interface.c
@@ -199,6 +199,7 @@ vshInterfaceListCollect(vshControl *ctl,
     int nActiveIfaces = 0;
     int nInactiveIfaces = 0;
     int nAllIfaces = 0;
+    int rc;
 
     /* try the list with flags support (0.10.2 and later) */
     if ((ret = virConnectListAllInterfaces(ctl->conn,
@@ -222,16 +223,17 @@ fallback:
     vshResetLibvirtError();
 
     if (flags & VIR_CONNECT_LIST_INTERFACES_ACTIVE) {
-        nActiveIfaces = virConnectNumOfInterfaces(ctl->conn);
-        if (nActiveIfaces < 0) {
+        rc = virConnectNumOfInterfaces(ctl->conn);
+        if (rc < 0) {
             vshError(ctl, "%s", _("Failed to list active interfaces"));
             goto cleanup;
         }
-        if (nActiveIfaces) {
+        if (rc) {
+            nActiveIfaces = rc;
             activeNames = vshMalloc(ctl, sizeof(char *) * nActiveIfaces);
 
-            if ((nActiveIfaces = virConnectListInterfaces(ctl->conn, activeNames,
-                                                          nActiveIfaces)) < 0) {
+            if ((rc = virConnectListInterfaces(ctl->conn, activeNames,
+                                               nActiveIfaces)) < 0) {
                 vshError(ctl, "%s", _("Failed to list active interfaces"));
                 goto cleanup;
             }
@@ -239,17 +241,17 @@ fallback:
     }
 
     if (flags & VIR_CONNECT_LIST_INTERFACES_INACTIVE) {
-        nInactiveIfaces = virConnectNumOfDefinedInterfaces(ctl->conn);
-        if (nInactiveIfaces < 0) {
+        rc = virConnectNumOfDefinedInterfaces(ctl->conn);
+        if (rc < 0) {
             vshError(ctl, "%s", _("Failed to list inactive interfaces"));
             goto cleanup;
         }
-        if (nInactiveIfaces) {
+        if (rc) {
+            nInactiveIfaces = rc;
             inactiveNames = vshMalloc(ctl, sizeof(char *) * nInactiveIfaces);
 
-            if ((nInactiveIfaces =
-                     virConnectListDefinedInterfaces(ctl->conn, inactiveNames,
-                                                     nInactiveIfaces)) < 0) {
+            if ((rc = virConnectListDefinedInterfaces(ctl->conn, inactiveNames,
+                                                      nInactiveIfaces)) < 0) {
                 vshError(ctl, "%s", _("Failed to list inactive interfaces"));
                 goto cleanup;
             }
-- 
1.8.1.4