Description:
------------
main/streams/plain_wrapper.c (5.0.5)
main/streams.c (4.4 and earlier)

In several places, the ^= operator is used to turn off a flag.  This is incorrect.  For example, stream_set_blocking() on a plain file hits this code in php_stdiop_set_option():

if (value)
    flags ^= O_NONBLOCK;
else
    flags |= O_NONBLOCK;

This should be:

if (value)
    flags &= ~O_NONBLOCK;
else
    flags |= O_NONBLOCK;

The same error is repeated elsewhere in the code.


Reproduce code:
---------------
$fp = fopen("test", "w");

stream_set_blocking($fp, true);
stream_set_blocking($fp, true);
stream_set_blocking($fp, true);
stream_set_blocking($fp, true);

fclose($fp);


Expected result:
----------------
The stream should remain in blocking mode throughout the script execution.


Actual result:
--------------
Here is abridged strace output showing the errant behavior.  Notice how O_NONBLOCK is being turned on and off alternately.

open("/home/askalski/test", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 4
fcntl64(4, F_SETFL, O_WRONLY|O_NONBLOCK) = 0
fcntl64(4, F_SETFL, O_WRONLY)           = 0
fcntl64(4, F_SETFL, O_WRONLY|O_NONBLOCK) = 0
fcntl64(4, F_SETFL, O_WRONLY)           = 0
close(4)                                = 0