--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+2010-01-07  Bruno Haible  <bruno@clisp.org>
+
+	mbslen: Avoid collision with system function.
+	* lib/string.in.h [MirBSD]: Include <wchar.h>.
+	(mbslen): Undefine first. Alias mbslen to rpl_mbslen.
+	* m4/mbslen.m4: New file.
+	* modules/mbslen (Files): Add it.
+	(configure.ac): Invoke gl_MBSLEN.
+	* m4/string_h.m4 (gl_HEADER_STRING_H_DEFAULTS): Initialize HAVE_MBSLEN.
+	* modules/string (Makefile.am): Substitute HAVE_MBSLEN.
+	Reported by Nelson H. F. Beebe <beebe@math.utah.edu>
+	via Ian Beckwith <ianb@erislabs.net>.
+
 2010-01-07  Bruno Haible  <bruno@clisp.org>
 
 	dirent: Document the last fix.

--- a/lib/string.in.h
+++ b/lib/string.in.h
@@ -31,6 +31,11 @@
 /* NetBSD 5.0 mis-defines NULL.  */
 #include <stddef.h>
 
+/* MirBSD defines mbslen as a macro.  */
+#if @GNULIB_MBSLEN@ && defined __MirBSD__
+# include <wchar.h>
+#endif
+
 #ifndef __attribute__
 /* This feature is available in gcc versions 2.5 and later.  */
 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 5)
@@ -439,6 +444,12 @@
 #if @GNULIB_MBSLEN@
 /* Return the number of multibyte characters in the character string STRING.
    This considers multibyte characters, unlike strlen, which counts bytes.  */
+# ifdef __MirBSD__  /* MirBSD defines mbslen as a macro.  Override it.  */
+#  undef mbslen
+# endif
+# if @HAVE_MBSLEN@  /* AIX, OSF/1, MirBSD define mbslen already in libc.  */
+#  define mbslen rpl_mbslen
+# endif
 extern size_t mbslen (const char *string) _GL_ARG_NONNULL ((1));
 #endif
 

new file mode 100644
--- /dev/null
+++ b/m4/mbslen.m4
@@ -0,0 +1,16 @@
+# mbslen.m4 serial 1
+dnl Copyright (C) 2010 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.
+
+AC_DEFUN([gl_MBSLEN],
+[
+  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([mbslen])
+  if test $ac_cv_func_mbslen = yes; then
+    HAVE_MBSLEN=1
+  else
+    HAVE_MBSLEN=0
+  fi
+])

--- a/m4/string_h.m4
+++ b/m4/string_h.m4
@@ -1,11 +1,11 @@
 # Configure a GNU-like replacement for <string.h>.
 
-# Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+# Copyright (C) 2007-2010 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
 
-# serial 9
+# serial 10
 
 # Written by Paul Eggert.
 
@@ -64,7 +64,8 @@
   GNULIB_MBSTOK_R=0;    AC_SUBST([GNULIB_MBSTOK_R])
   GNULIB_STRERROR=0;    AC_SUBST([GNULIB_STRERROR])
   GNULIB_STRSIGNAL=0;   AC_SUBST([GNULIB_STRSIGNAL])
-  GNULIB_STRVERSCMP=0;   AC_SUBST([GNULIB_STRVERSCMP])
+  GNULIB_STRVERSCMP=0;  AC_SUBST([GNULIB_STRVERSCMP])
+  HAVE_MBSLEN=0;        AC_SUBST([HAVE_MBSLEN])
   dnl Assume proper GNU behavior unless another module says otherwise.
   HAVE_DECL_MEMMEM=1;           AC_SUBST([HAVE_DECL_MEMMEM])
   HAVE_MEMPCPY=1;               AC_SUBST([HAVE_MEMPCPY])

--- a/modules/mbslen
+++ b/modules/mbslen
@@ -3,12 +3,14 @@
 
 Files:
 lib/mbslen.c
+m4/mbslen.m4
 
 Depends-on:
 mbuiter
 string
 
 configure.ac:
+gl_MBSLEN
 gl_STRING_MODULE_INDICATOR([mbslen])
 
 Makefile.am:

--- a/modules/string
+++ b/modules/string
@@ -59,6 +59,7 @@
 	      -e 's|@''GNULIB_STRERROR''@|$(GNULIB_STRERROR)|g' \
 	      -e 's|@''GNULIB_STRSIGNAL''@|$(GNULIB_STRSIGNAL)|g' \
 	      -e 's|@''GNULIB_STRVERSCMP''@|$(GNULIB_STRVERSCMP)|g' \
+	      -e 's|@''HAVE_MBSLEN''@|$(HAVE_MBSLEN)|g' \
 	      -e 's|@''HAVE_DECL_MEMMEM''@|$(HAVE_DECL_MEMMEM)|g' \
 	      -e 's|@''HAVE_MEMPCPY''@|$(HAVE_MEMPCPY)|g' \
 	      -e 's|@''HAVE_DECL_MEMRCHR''@|$(HAVE_DECL_MEMRCHR)|g' \