ftpserver.pl: Added SELECT check to IMAP SEARCH command

tests/ftpserver.pl

@@ -1034,9 +1034,13 @@ sub STATUS_imap {
 
 sub SEARCH_imap {
     my ($what) = @_;
-    my $testno = $selected;
     fix_imap_params($what);
 
+    if ($selected eq "") {
+        sendcontrol "$cmdid BAD Command received in Invalid state\r\n";
+    else {
+        my $testno = $selected;
+
         logmsg "SEARCH_imap got test $testno\n";
 
         $testno =~ s/^([^0-9]*)//;
@@ -1055,6 +1059,7 @@ sub SEARCH_imap {
         }
 
         sendcontrol "$cmdid OK SEARCH completed\r\n";
+    }
 
     return 0;
 }