Description:
------------
acos() function returns "0" rather than "NAN" for values of |x| > 1. Among other things this causes test ext/standard/tests/math/bug25665.phpt to fail.

This may be caused by ambiguous handling of out-of-range arguments in the Solaris implementation of acos(). From the acos() man page: "If the value of x is not in the range [-1,1], and is not +-Inf or NaN, either 0.0 or NaN is returned and errno is set to EDOM."

Configure line:

./configure  --with-apxs=/www/apache/bin/apxs --with-mssql=/www/freetds063 --enable-ftp

Dependencies:

        libsybdb.so.5 =>         /www/freetds063/lib/libsybdb.so.5
        libnsl.so.1 =>   /lib/libnsl.so.1
        libsocket.so.1 =>        /lib/libsocket.so.1
        libc.so.1 =>     /lib/libc.so.1
        libresolv.so.2 =>        /lib/libresolv.so.2
        libm.so.1 =>     /lib/libm.so.1
        libdl.so.1 =>    /lib/libdl.so.1
        libz.so.1 =>     /lib/libz.so.1
        libxml2.so.2 =>  /usr/local/lib/libxml2.so.2
        libpthread.so.1 =>       /lib/libpthread.so.1
        libiconv.so.2 =>         /usr/local/lib/libiconv.so.2
        libgcc_s.so.1 =>         /usr/local/lib/libgcc_s.so.1
        libmp.so.2 =>    /lib/libmp.so.2
        /usr/platform/SUNW,UltraAX-i2/lib/libc_psr.so.1
        libthread.so.1 =>        /lib/libthread.so.1
        librt.so.1 =>    /lib/librt.so.1
        libaio.so.1 =>   /lib/libaio.so.1
        libmd5.so.1 =>   /lib/libmd5.so.1
        /usr/platform/SUNW,UltraAX-i2/lib/libmd5_psr.so.1


gcc -v output:

Reading specs from /usr/local/lib/gcc/sparc-sun-solaris2.9/3.4.2/specs
Configured with: ../configure --with-as=/usr/ccs/bin/as --with-ld=/usr/ccs/bin/ld --disable-nls
Thread model: posix
gcc version 3.4.2



Reproduce code:
---------------
<?php
set_time_limit(5);
var_dump(acos(1.01));
var_dump(log(0));
?>


Expected result:
----------------
float(NAN)
float(-INF)

Actual result:
--------------
float(0)
float(-INF)