--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,19 @@
 2012-02-27  Bruno Haible  <bruno@clisp.org>
 
+	remainder-ieee: Work around test failure on OSF/1.
+	* m4/remainder-ieee.m4: New file.
+	* m4/remainder.m4 (gl_FUNC_REMAINDER): If gl_FUNC_REMAINDER_IEEE is
+	present, test whether remainder works with a zero second argument.
+	Replace it if not.
+	* lib/math.in.h (remainder): Override if REPLACE_REMAINDER is 1.
+	* m4/math_h.m4 (gl_MATH_H_DEFAULTS): Initialize REPLACE_REMAINDER.
+	* modules/math (Makefile.am): Substitute REPLACE_REMAINDER.
+	* modules/remainder (configure.ac): Consider REPLACE_REMAINDER.
+	(Depends-on): Update dependencies.
+	* modules/remainder-ieee (Files): Add m4/remainder-ieee.m4.
+	(configure.ac): Invoke gl_FUNC_REMAINDER_IEEE.
+	* doc/posix-functions/remainder.texi: Mention the remainder-ieee module.
+
 	Tests for module 'remainderl-ieee'.
 	* modules/remainderl-ieee-tests: New file.
 	* tests/test-remainderl-ieee.c: New file.

--- a/doc/posix-functions/remainder.texi
+++ b/doc/posix-functions/remainder.texi
@@ -4,9 +4,9 @@
 
 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/remainder.html}
 
-Gnulib module: remainder
+Gnulib module: remainder or remainder-ieee
 
-Portability problems fixed by Gnulib:
+Portability problems fixed by either Gnulib module @code{remainder} or @code{remainder-ieee}:
 @itemize
 @item
 This function is missing on some platforms:
@@ -16,6 +16,13 @@
 IRIX 5.3.
 @end itemize
 
+Portability problems fixed by Gnulib module @code{remainder-ieee}:
+@itemize
+@item
+This function has problems when the second argument is zero on some platforms:
+OSF/1 5.1.
+@end itemize
+
 Portability problems not fixed by Gnulib:
 @itemize
 @end itemize

--- a/lib/math.in.h
+++ b/lib/math.in.h
@@ -996,10 +996,19 @@
 #endif
 
 #if @GNULIB_REMAINDER@
-# if !@HAVE_REMAINDER@ || !@HAVE_DECL_REMAINDER@
+# if @REPLACE_REMAINDER@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef remainder
+#   define remainder rpl_remainder
+#  endif
+_GL_FUNCDECL_RPL (remainder, double, (double x, double y));
+_GL_CXXALIAS_RPL (remainder, double, (double x, double y));
+# else
+#  if !@HAVE_REMAINDER@ || !@HAVE_DECL_REMAINDER@
 _GL_FUNCDECL_SYS (remainder, double, (double x, double y));
+#  endif
+_GL_CXXALIAS_SYS (remainder, double, (double x, double y));
 # endif
-_GL_CXXALIAS_SYS (remainder, double, (double x, double y));
 _GL_CXXALIASWARN (remainder);
 #elif defined GNULIB_POSIXCHECK
 # undef remainder

--- a/m4/math_h.m4
+++ b/m4/math_h.m4
@@ -1,4 +1,4 @@
-# math_h.m4 serial 68
+# math_h.m4 serial 69
 dnl Copyright (C) 2007-2012 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -228,6 +228,7 @@
   REPLACE_MODFF=0;             AC_SUBST([REPLACE_MODFF])
   REPLACE_MODFL=0;             AC_SUBST([REPLACE_MODFL])
   REPLACE_NAN=0;               AC_SUBST([REPLACE_NAN])
+  REPLACE_REMAINDER=0;         AC_SUBST([REPLACE_REMAINDER])
   REPLACE_ROUND=0;             AC_SUBST([REPLACE_ROUND])
   REPLACE_ROUNDF=0;            AC_SUBST([REPLACE_ROUNDF])
   REPLACE_ROUNDL=0;            AC_SUBST([REPLACE_ROUNDL])

new file mode 100644
--- /dev/null
+++ b/m4/remainder-ieee.m4
@@ -0,0 +1,15 @@
+# remainder-ieee.m4 serial 1
+dnl Copyright (C) 2012 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.
+
+dnl This macro is in a separate file (not in remainder.m4 and not inlined in the
+dnl module description), so that gl_FUNC_REMAINDER can test whether 'aclocal'
+dnl has found uses of this macro.
+
+AC_DEFUN([gl_FUNC_REMAINDER_IEEE],
+[
+  m4_divert_text([INIT_PREPARE], [gl_remainder_required=ieee])
+  AC_REQUIRE([gl_FUNC_REMAINDER])
+])

--- a/m4/remainder.m4
+++ b/m4/remainder.m4
@@ -1,4 +1,4 @@
-# remainder.m4 serial 1
+# remainder.m4 serial 2
 dnl Copyright (C) 2012 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -6,6 +6,7 @@
 
 AC_DEFUN([gl_FUNC_REMAINDER],
 [
+  m4_divert_text([DEFAULTS], [gl_remainder_required=plain])
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
 
   dnl Test whether remainder() is declared. On IRIX 5.3 it is not declared.
@@ -50,9 +51,59 @@
       REMAINDER_LIBM=-lm
     fi
   fi
-  if test $gl_cv_func_remainder_no_libm = no \
-     && test $gl_cv_func_remainder_in_libm = no; then
+  if test $gl_cv_func_remainder_no_libm = yes \
+     || test $gl_cv_func_remainder_in_libm = yes; then
+    :
+    m4_ifdef([gl_FUNC_REMAINDER_IEEE], [
+      if test $gl_remainder_required = ieee && test $REPLACE_REMAINDER = 0; then
+        AC_CACHE_CHECK([whether remainder works according to ISO C 99 with IEC 60559],
+          [gl_cv_func_remainder_ieee],
+          [
+            save_LIBS="$LIBS"
+            LIBS="$LIBS $REMAINDER_LIBM"
+            AC_RUN_IFELSE(
+              [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+/* Compare two numbers with ==.
+   This is a separate function because IRIX 6.5 "cc -O" miscompiles an
+   'x == x' test.  */
+static int
+numeric_equal (double x, double y)
+{
+  return x == y;
+}
+static double dummy (double x, double y) { return 0; }
+int main (int argc, char *argv[])
+{
+  double (*my_remainder) (double, double) = argc ? remainder : dummy;
+  double i;
+  double f;
+  /* Test remainder(...,0.0).
+     This test fails on OSF/1 5.1.  */
+  f = my_remainder (2.0, 0.0);
+  if (numeric_equal (f, f))
+    return 1;
+  return 0;
+}
+              ]])],
+              [gl_cv_func_remainder_ieee=yes],
+              [gl_cv_func_remainder_ieee=no],
+              [gl_cv_func_remainder_ieee="guessing no"])
+            LIBS="$save_LIBS"
+          ])
+        case "$gl_cv_func_remainder_ieee" in
+          *yes) ;;
+          *) REPLACE_REMAINDER=1 ;;
+        esac
+      fi
+    ])
+  else
     HAVE_REMAINDER=0
+  fi
+  if test $HAVE_REMAINDER = 0 || test $REPLACE_REMAINDER = 1; then
     dnl Find libraries needed to link lib/remainder.c.
     AC_REQUIRE([gl_FUNC_ROUND])
     AC_REQUIRE([gl_FUNC_FMA])

--- a/modules/math
+++ b/modules/math
@@ -198,6 +198,7 @@
 	      -e 's|@''REPLACE_MODFF''@|$(REPLACE_MODFF)|g' \
 	      -e 's|@''REPLACE_MODFL''@|$(REPLACE_MODFL)|g' \
 	      -e 's|@''REPLACE_NAN''@|$(REPLACE_NAN)|g' \
+	      -e 's|@''REPLACE_REMAINDER''@|$(REPLACE_REMAINDER)|g' \
 	      -e 's|@''REPLACE_ROUND''@|$(REPLACE_ROUND)|g' \
 	      -e 's|@''REPLACE_ROUNDF''@|$(REPLACE_ROUNDF)|g' \
 	      -e 's|@''REPLACE_ROUNDL''@|$(REPLACE_ROUNDL)|g' \

--- a/modules/remainder
+++ b/modules/remainder
@@ -8,12 +8,12 @@
 
 Depends-on:
 math
-round           [test $HAVE_REMAINDER = 0]
-fma             [test $HAVE_REMAINDER = 0]
+round           [test $HAVE_REMAINDER = 0 || test $REPLACE_REMAINDER = 1]
+fma             [test $HAVE_REMAINDER = 0 || test $REPLACE_REMAINDER = 1]
 
 configure.ac:
 gl_FUNC_REMAINDER
-if test $HAVE_REMAINDER = 0; then
+if test $HAVE_REMAINDER = 0 || test $REPLACE_REMAINDER = 1; then
   AC_LIBOBJ([remainder])
 fi
 gl_MATH_MODULE_INDICATOR([remainder])

--- a/modules/remainder-ieee
+++ b/modules/remainder-ieee
@@ -2,12 +2,14 @@
 remainder() function according to ISO C 99 with IEC 60559.
 
 Files:
+m4/remainder-ieee.m4
 
 Depends-on:
 remainder
 fpieee
 
 configure.ac:
+gl_FUNC_REMAINDER_IEEE
 
 Makefile.am: