virsh: fix entering interactive session

When entering an interactive session, that is, without a command
specified:

  virsh --connect $URI

virsh currently segfaults because it tries to access
ctl->cmd->def->handler and the ctl->cmd is NULL.

Fix by checking if ctl->cmd is not NULL before doing further checks.

Fixes: b489eb8d6b52d4183754a5d1da55006148a331e4
Signed-off-by: Roman Bogorodskiy <bogorodskiy@gmail.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>

diff --git a/tools/virsh.c b/tools/virsh.c
index 72d233f98d0b3b006f3aa5c30fd6e605b251342a..401d4f9787bd0c8630f2e1ece513fe681e387e8f 100644 (file)
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -126,7 +126,7 @@ virshConnect(vshControl *ctl, const char *uri, bool readonly)
         virErrorPtr err;
         virConnectAuthPtr auth = virConnectAuthPtrDefault;
 
-        if (ctl->cmd->def->handler == cmdComplete) {
+        if (ctl->cmd && ctl->cmd->def->handler == cmdComplete) {
             /* When running from a bash completer we need to avoid any kind of
              * keyboard input (e.g. ssh asking for a password). To achieve
              * this, provide no authentication callbacks. */