Merge mysql.com:/M41/bug20303-4.1 into mysql.com:/M50/bug20303-5.0

mysql-test/mysql-test-run.pl:
  Auto merged

mysql-test/mysql-test-run.pl

@@ -671,6 +671,12 @@ sub command_line_setup () {
     {
       push(@opt_extra_mysqld_opt, $arg);
     }
+    elsif ( $arg =~ /^--$/ )
+    {
+      # It is an effect of setting 'pass_through' in option processing
+      # that the lone '--' separating options from arguments survives,
+      # simply ignore it.
+    }
     elsif ( $arg =~ /^-/ )
     {
       usage("Invalid option \"$arg\"");