virsh: don't reject undefine on active domain

The public API documents that undefine may be used to transition a
running persistent domain into a transient one.  Many drivers still
do not support this usage, but virsh shouldn't be getting in the
way of those that do support it.

This also drops a redundant conditional; vshCommandOptString
guaranteed that name was non-NULL.

* tools/virsh.c (cmdUndefine): Allow undefine on active domains;
the drivers may still reject it, but it is a valid API usage.
* tests/undefine (error): Fix the test to match.

tests/undefine

 #!/bin/sh
 # exercise virsh's "undefine" command
 
-# Copyright (C) 2008-2009 Red Hat, Inc.
+# Copyright (C) 2008-2009, 2011 Red Hat, Inc.
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -30,6 +30,7 @@ fi
 fail=0
 
 # Attempt to undefine a running domain, by domain name.
+# Although the API allows this, the test hypervisor does not.
 $abs_top_builddir/tools/virsh -q -c test:///default undefine test > out 2>&1
 test $? = 1 || fail=1
 cat <<\EOF > exp || fail=1
@@ -38,12 +39,12 @@ error: internal error Domain 'test' is still running
 EOF
 compare exp out || fail=1
 
-# A different diagnostic when specifying a domain ID
+# A similar diagnostic when specifying a domain ID
 $abs_top_builddir/tools/virsh -q -c test:///default undefine 1 > out 2>&1
 test $? = 1 || fail=1
 cat <<\EOF > exp || fail=1
-error: a running domain like 1 cannot be undefined;
-to undefine, first shutdown then undefine using its name or UUID
+error: Failed to undefine domain 1
+error: internal error Domain 'test' is still running
 EOF
 compare exp out || fail=1
 

tools/virsh.c

@@ -1431,7 +1431,6 @@ cmdUndefine(vshControl *ctl, const vshCmd *cmd)
     virDomainPtr dom;
     bool ret = true;
     const char *name = NULL;
-    int id;
     int flags = 0;
     int managed_save = vshCommandOptBool(cmd, "managed-save");
     int has_managed_save = 0;
@@ -1449,19 +1448,7 @@ cmdUndefine(vshControl *ctl, const vshCmd *cmd)
     if (vshCommandOptString(cmd, "domain", &name) <= 0)
         return false;
 
-    if (name && virStrToLong_i(name, NULL, 10, &id) == 0
-        && id >= 0 && (dom = virDomainLookupByID(ctl->conn, id))) {
-        vshError(ctl,
-                 _("a running domain like %s cannot be undefined;\n"
-                   "to undefine, first shutdown then undefine"
-                   " using its name or UUID"),
-                 name);
-        virDomainFree(dom);
-        return false;
-    }
-    if (!(dom = vshCommandOptDomainBy(ctl, cmd, &name,
-                                      VSH_BYNAME|VSH_BYUUID)))
-        return false;
+    if (!(dom = vshCommandOptDomain(ctl, cmd, &name)))
 
     has_managed_save = virDomainHasManagedSaveImage(dom, 0);
     if (has_managed_save < 0) {