[Vortex] CHANGE-NOTIFICATION: vortex-conn-opts-01.txt

[Francis Brosnan Blazquez]

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       ####     Change notification     ####
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    Change Id: vortex-conn-opts-01
 Project name: Vortex Library
  Included in: already included and to be shipped with next stable release
               1.1.10
       Status: NOTIFY
       Author: Francis Brosnan Blázquez

Motivation
~~~~~~~~~~

Vortex provides a way to setup connection options before the connect
operation takes place using vortex_connection_opts_new. 

In this context, vortex also provides a macro called CONN_OPTS that
eases the process. However, this macro was using a definition
__VA_ARGS__ not available in many compilers (namely visual studio
ones).

Change Description
~~~~~~~~~~~~~~~~~~

Now the macro has been rewritten in a way it provides same features
but now the programmer must provide the last VORTEX_OPTS_END to
finalize the variadic macro.

So, before we were writing:

  opts = CONN_OPTS (VORTEX_SERVERNAME_FEATURE, "some-server-name.local");

Now, we do so like:

  opts = CONN_OPTS (VORTEX_SERVERNAME_FEATURE, "some-server-name.local", VORTEX_OPTS_END);

Solution to incompatibility
~~~~~~~~~~~~~~~~~~~~~~~~~~~

Any application that were using this macro will have to add
VORTEX_OPTS_END to avoid wrong memory access (because variadic
argument list is not ended).

However, any application that were compiled with old headers, will
keep working without any problem even with newer libvortex-1.1
compiled (because the macro expanded in the past adding
VORTEX_OPTS_END automatically).

To recap, the change is only required in the case the application is
recompiled against newer vortex versions (starting from 1.1.10).

References
~~~~~~~~~~
[1] Project link: 
    http://vortex.aspl.es

[2] Change notification published by the project:
    http://vortex.aspl.es/doc.html

[3] Change notification definition
    http://www.aspl.es/change/change-notification.txt