compilation with libeditpreferred is broken

When I try compile postgresql with --libeditpreferred option,
compilation fails when readline is also installed on the system. You can
see error report on:

http://www.pgbuildfarm.org/cgi-bin/show_log.pl?nm=dot_moth&dt=2009-08-06%2012:46:04

The main problem is in src/bin/psql/input.h where is following ifdef
magic:

  #define USE_READLINE 1
  #if defined(HAVE_READLINE_READLINE_H)
      #include <readline/readline.h>
  #elif defined(HAVE_EDITLINE_READLINE_H)
      #include <editline/readline.h>
  #elif defined(HAVE_READLINE_H)
      #include <readline.h>
  #endif

  #if defined(HAVE_READLINE_HISTORY_H)
      #include <readline/history.h>
  #elif defined(HAVE_EDITLINE_HISTORY_H)
      #include <editline/history.h>
  #elif defined(HAVE_HISTORY_H)
      #include <history.h>
  #endif


The problem is that libedit does not distribute editline/history.h and
configure detects that there is readline/history.h and sets
HAVE_READLINE_HISTORY_H macro. Finally input.h includes
editline/readline.h and readline/history.h which causes symbol
conflicts.

It seems to me that editline never distributed history.h file and
HAVE_EDITLINE_HISTORY_H is nonsense. But I'm not sure.

I attached suggested fix, but it needs also some work in ./configure -
depends if libedit/history.h existed. Anyone knows a history?

I need to backported this fix for branches 8.2 - 8.4, because
OpenSolaris PostgreSQL binaries build is broken now.

    Zdenek