Handling macro change in an exported library header

[Nikita Youshchenko <yoush@debian.org>]

Hello.

To fix #486693, I need to apply a patch that changes #define'd macro in an 
exported library header.

The pattern is:

extern int foo(char *param1, int param2);
#define bar(param) foo(param, expr(param))

and changed thing is expr(param)

Looks like binary interface of the shared library does not change, however 
strictly saying any user of the library that uses bar() macro needs to 
recompile his code.

Any comments on how to handle this change in packaging properly?

Nikita