savestring() macro in general.h runs function arguments twice.

[John E. Malmberg]

The execute_cmd.c module uses make_command_string() as a parameter to 
the savestring() macro.

This causes the savestring() macro to call that function twice().

I have not done any timing tests to see how this is impacting 
performance, but it definitely shows up when stepping through commands 
doing debugging.

This issue was first noticed in bash 1.14.7 and is also seen in the 
current bash 4.2.39.

I have locally patched execute_cmd.c to use an intermediate variable. 
The proper fix should probably be in general.h.

I did not find any other cases where a function was passed as a parameter.

Bash 4.2.39 on VMS is now able to run its own configure script and also 
the curl 7.20 configure script which is a bigger torture.

EAGLE> bash --version
GNU bash, version 4.2.39(1)-release (alpha-dec-vms)
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later 
<http://gnu.org/licenses/gpl.html>

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
GNV-3.0-1-JEM-1 Nov 23 2012 09:17:12

Regards,
-John
wb8tyw@qsl.network
Personal Opinion Only