Depends-on:
math
-modf [test $HAVE_MODFF = 0]
+extensions
+modf [test $HAVE_MODFF = 0 || test $REPLACE_MODFF = 1]
configure.ac:
gl_FUNC_MODFF
-if test $HAVE_MODFF = 0; then
+if test $HAVE_MODFF = 0 || test $REPLACE_MODFF = 1; then
AC_LIBOBJ([modff])
fi
gl_MATH_MODULE_INDICATOR([modff])