Description:
------------
I have a CLI script that hangs on termination. The script will call exit when it is done, the shutdown function will be called, destructors will be called, and then it just waits for nothing to happen. I have to manually terminate the process to get it to exit. It does not consume any resources, it just hangs forever. The same behaviour is observed with the die function. It appears on both 5.5 and 5.6.

Test script:
---------------
I do not have a simple test script that can reproduce it at the moment, but I have  a log from running the script with strace. 

I have uploaded the trace to the following location: http://www.filedropper.com/trace

The end of the trace looks like this, it seems to be polling for something.

fstat(12, {st_mode=S_IFREG|0777, st_size=1314, ...}) = 0
fstat(12, {st_mode=S_IFREG|0777, st_size=1314, ...}) = 0
fstat(12, {st_mode=S_IFREG|0777, st_size=1314, ...}) = 0
fstat(12, {st_mode=S_IFREG|0777, st_size=1314, ...}) = 0
mmap(NULL, 1314, PROT_READ, MAP_SHARED, 12, 0) = 0x7fc092237000
munmap(0x7fc092237000, 1314)            = 0
close(12)                               = 0
close(3)                                = 0
close(4)                                = 0
write(6, "\1\0\0\0\0\0\0\0", 8)         = 8
write(11, "\1\0\0\0\1", 5)              = 5
shutdown(11, SHUT_RDWR)                 = 0
close(11)                               = 0
munmap(0x7fc087db9000, 266240)          = 0
close(2)                                = 0
close(1)                                = 0
munmap(0x7fc092235000, 4096)            = 0
close(0)                                = 0
munmap(0x7fc092236000, 4096)            = 0
brk(0x2d38000)                          = 0x2d38000
munmap(0x7fc087d37000, 266240)          = 0
munmap(0x7fc087d78000, 266240)          = 0
munmap(0x7fc087e39000, 266240)          = 0
munmap(0x7fc087e7a000, 266240)          = 0
munmap(0x7fc087ebb000, 266240)          = 0
munmap(0x7fc087efc000, 266240)          = 0
munmap(0x7fc087f3d000, 266240)          = 0
munmap(0x7fc087f7e000, 266240)          = 0
munmap(0x7fc087fbf000, 266240)          = 0
munmap(0x7fc08c035000, 266240)          = 0
munmap(0x7fc08c076000, 266240)          = 0
munmap(0x7fc08c0b7000, 266240)          = 0
munmap(0x7fc092055000, 266240)          = 0
write(10, "\1\0\0\0\0\0\0\0", 8)        = 8
poll([{fd=5, events=POLLIN}], 1, 4294967295
Process 3037 detached
 <detached ...>

Expected result:
----------------
Script should terminate on exit

Actual result:
--------------
Script hangs forever