>From c8eb1af611279eaebff505dbfe176885ca3b0fdc Mon Sep 17 00:00:00 2001
From: Bruno Haible <address@hidden>
Date: Sat, 9 May 2020 02:55:06 +0200
Subject: [PATCH 2/2] c32rtomb: Avoid compilation failure on Haiku.

* m4/c32rtomb.m4 (gl_FUNC_C32RTOMB): Test for c32rtomb without excluding
inline definitions.
* doc/posix-functions/c32rtomb.texi: Mention the Haiku problem.
---
 ChangeLog                         |  7 +++++++
 doc/posix-functions/c32rtomb.texi |  3 +++
 m4/c32rtomb.m4                    | 20 +++++++++++++++++---
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 53a672a..c22d515 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2020-05-08  Bruno Haible  <address@hidden>
 
+	c32rtomb: Avoid compilation failure on Haiku.
+	* m4/c32rtomb.m4 (gl_FUNC_C32RTOMB): Test for c32rtomb without excluding
+	inline definitions.
+	* doc/posix-functions/c32rtomb.texi: Mention the Haiku problem.
+
+2020-05-08  Bruno Haible  <address@hidden>
+
 	mbrtoc32: Avoid compilation failure on Haiku.
 	* m4/mbrtoc32.m4 (gl_CHECK_FUNC_MBRTOC32): New macro.
 	(gl_FUNC_MBRTOC32, gl_MBRTOC32_SANITYCHECK): Use it instead of
diff --git a/doc/posix-functions/c32rtomb.texi b/doc/posix-functions/c32rtomb.texi
index 4a1a617..fd4ada6 100644
--- a/doc/posix-functions/c32rtomb.texi
+++ b/doc/posix-functions/c32rtomb.texi
@@ -16,4 +16,7 @@ AIX 7.2.
 
 Portability problems not fixed by Gnulib:
 @itemize
+@item
+This function is only defined as an inline function on some platforms:
+Haiku 2020.
 @end itemize
diff --git a/m4/c32rtomb.m4 b/m4/c32rtomb.m4
index 4cf0e4d..f55ce31 100644
--- a/m4/c32rtomb.m4
+++ b/m4/c32rtomb.m4
@@ -1,4 +1,4 @@
-# c32rtomb.m4 serial 1
+# c32rtomb.m4 serial 2
 dnl Copyright (C) 2020 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -10,8 +10,22 @@ AC_DEFUN([gl_FUNC_C32RTOMB],
 
   AC_REQUIRE([gl_MBRTOC32_SANITYCHECK])
 
-  AC_CHECK_FUNCS_ONCE([c32rtomb])
-  if test $ac_cv_func_c32rtomb = no; then
+  dnl We can't use AC_CHECK_FUNC here, because c32rtomb() is defined as a
+  dnl static inline function on Haiku 2020.
+  AC_CACHE_CHECK([for c32rtomb], [gl_cv_func_c32rtomb],
+    [AC_LINK_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <stdlib.h>
+            #include <uchar.h>
+          ]],
+          [[char buf[8];
+            return c32rtomb (buf, 0, NULL) == 0;
+          ]])
+       ],
+       [gl_cv_func_c32rtomb=yes],
+       [gl_cv_func_c32rtomb=no])
+    ])
+  if test $gl_cv_func_c32rtomb = no; then
     HAVE_C32RTOMB=0
   else
     dnl When we override mbrtoc32, redefining the meaning of the char32_t
-- 
2.7.4