tdelete on OpenBSD

[Bruno Haible]

On OpenBSD 4.0, the tdelete() function has an incorrect return value when
removing the last element from a tree. This works around it.

2008-01-09  Bruno Haible  <address@hidden>

        Work around OpenBSD 4.0 tdelete() bug.
        * m4/tsearch.m4 (gl_FUNC_TSEARCH): Also check tdelete's return value.
        * lib/search.in.h: If REPLACE_TSEARCH is 1, define tsearch etc. as
        macros and don't redefine the enum values.
        * m4/search_h.m4 (gl_SEARCH_H_DEFAULTS): Initialize REPLACE_TSEARCH.
        * modules/search (Makefile.am): Also substitute REPLACE_TSEARCH.
        * doc/functions/tdelete.texi: Document the OpenBSD 4.0 bug.

*** doc/functions/tdelete.texi.orig     2008-01-10 02:38:09.000000000 +0100
--- doc/functions/tdelete.texi  2008-01-10 02:25:32.000000000 +0100
***************
*** 11,16 ****
--- 11,20 ----
  @item
  This function is missing on some platforms:
  mingw, BeOS.
+ @item
+ @code{tdelete} returns @code{NULL} when removing the last element of a tree
+ on some platforms:
+ OpenBSD 4.0.
  @end itemize
  
  Portability problems not fixed by Gnulib:
*** lib/search.in.h.orig        2008-01-10 02:38:09.000000000 +0100
--- lib/search.in.h     2008-01-10 02:25:32.000000000 +0100
***************
*** 1,6 ****
  /* A GNU-like <search.h>.
  
!    Copyright (C) 2007 Free Software Foundation, Inc.
  
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
--- 1,6 ----
  /* A GNU-like <search.h>.
  
!    Copyright (C) 2007-2008 Free Software Foundation, Inc.
  
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
***************
*** 35,46 ****
  
  
  #if @GNULIB_TSEARCH@
! # if address@hidden@
  
  /* See <http://www.opengroup.org/susv3xbd/search.h.html>,
         <http://www.opengroup.org/susv3xsh/tsearch.html>
     for details.  */
  
  typedef enum
  {
    preorder,
--- 35,53 ----
  
  
  #if @GNULIB_TSEARCH@
! # if @REPLACE_TSEARCH@
! #  define tsearch rpl_tsearch
! #  define tfind rpl_tfind
! #  define tdelete rpl_tdelete
! #  define twalk rpl_twalk
! # endif
! # if address@hidden@ || @REPLACE_TSEARCH@
  
  /* See <http://www.opengroup.org/susv3xbd/search.h.html>,
         <http://www.opengroup.org/susv3xsh/tsearch.html>
     for details.  */
  
+ #  if address@hidden@
  typedef enum
  {
    preorder,
***************
*** 49,54 ****
--- 56,62 ----
    leaf
  }
  VISIT;
+ #  endif
  
  /* Searches an element in the tree *VROOTP that compares equal to KEY.
     If one is found, it is returned.  Otherwise, a new element equal to KEY
*** m4/search_h.m4.orig 2008-01-10 02:38:09.000000000 +0100
--- m4/search_h.m4      2008-01-10 02:25:32.000000000 +0100
***************
*** 1,5 ****
! # search_h.m4 serial 2
! dnl Copyright (C) 2007 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
  dnl with or without modifications, as long as this notice is preserved.
--- 1,5 ----
! # search_h.m4 serial 3
! dnl Copyright (C) 2007-2008 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
  dnl with or without modifications, as long as this notice is preserved.
***************
*** 27,31 ****
  [
    GNULIB_TSEARCH=0; AC_SUBST([GNULIB_TSEARCH])
    dnl Assume proper GNU behavior unless another module says otherwise.
!   HAVE_TSEARCH=1; AC_SUBST([HAVE_TSEARCH])
  ])
--- 27,32 ----
  [
    GNULIB_TSEARCH=0; AC_SUBST([GNULIB_TSEARCH])
    dnl Assume proper GNU behavior unless another module says otherwise.
!   HAVE_TSEARCH=1;    AC_SUBST([HAVE_TSEARCH])
!   REPLACE_TSEARCH=0; AC_SUBST([REPLACE_TSEARCH])
  ])
*** m4/tsearch.m4.orig  2008-01-10 02:38:09.000000000 +0100
--- m4/tsearch.m4       2008-01-10 02:25:32.000000000 +0100
***************
*** 1,5 ****
! # tsearch.m4 serial 2
! dnl Copyright (C) 2006-2007 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
  dnl with or without modifications, as long as this notice is preserved.
--- 1,5 ----
! # tsearch.m4 serial 3
! dnl Copyright (C) 2006-2008 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
  dnl with or without modifications, as long as this notice is preserved.
***************
*** 8,14 ****
  [
    AC_REQUIRE([gl_SEARCH_H_DEFAULTS])
    AC_CHECK_FUNCS([tsearch])
!   if test $ac_cv_func_tsearch = no; then
      HAVE_TSEARCH=0
      AC_LIBOBJ([tsearch])
      gl_PREREQ_TSEARCH
--- 8,52 ----
  [
    AC_REQUIRE([gl_SEARCH_H_DEFAULTS])
    AC_CHECK_FUNCS([tsearch])
!   if test $ac_cv_func_tsearch = yes; then
!     dnl On OpenBSD 4.0, the return value of tdelete() is incorrect.
!     AC_REQUIRE([AC_PROG_CC])
!     AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
!     AC_CACHE_CHECK([whether tdelete works], [gl_cv_func_tdelete_works],
!       [
!         AC_TRY_RUN([
! #include <stddef.h>
! #include <search.h>
! static int
! cmp_fn (const void *a, const void *b)
! {
!   return *(const int *) a - *(const int *) b;
! }
! int
! main ()
! {
!   int x = 0;
!   void *root = NULL;
!   if (!(tfind (&x, &root, cmp_fn) == NULL)) return 1;
!   tsearch (&x, &root, cmp_fn);
!   if (!(tfind (&x, &root, cmp_fn) != NULL)) return 1;
!   if (!(tdelete (&x, &root, cmp_fn) != NULL)) return 1;
!   return 0;
! }], [gl_cv_func_tdelete_works=yes], [gl_cv_func_tdelete_works=no],
!             [case "$host_os" in
!                openbsd*) gl_cv_func_tdelete_works="guessing no";;
!                *)        gl_cv_func_tdelete_works="guessing yes";;
!              esac
!             ])
!       ])
!     case "$gl_cv_func_tdelete_works" in
!       *no)
!         REPLACE_TSEARCH=1
!         AC_LIBOBJ([tsearch])
!         gl_PREREQ_TSEARCH
!         ;;
!     esac
!   else
      HAVE_TSEARCH=0
      AC_LIBOBJ([tsearch])
      gl_PREREQ_TSEARCH
*** modules/search.orig 2008-01-10 02:38:09.000000000 +0100
--- modules/search      2008-01-10 02:25:32.000000000 +0100
***************
*** 25,30 ****
--- 25,31 ----
              -e 's|@''NEXT_SEARCH_H''@|$(NEXT_SEARCH_H)|g' \
              -e 's|@''GNULIB_TSEARCH''@|$(GNULIB_TSEARCH)|g' \
              -e 's|@''HAVE_TSEARCH''@|$(HAVE_TSEARCH)|g' \
+             -e 's|@''REPLACE_TSEARCH''@|$(REPLACE_TSEARCH)|g' \
              -e '/definition of GL_LINK_WARNING/r $(LINK_WARNING_H)' \
              < $(srcdir)/search.in.h; \
        } > address@hidden