Description:
------------
Settings <?php setlocale(LC_ALL, 'danish') ?> and running a curl request against a hostname that returns a special timeout (firewall block), makes PHP segfault.

If one does NOT use LC_ALL, but LC_MESSAGES or all of the LC_*, it does not crash. It _only_ happens for LC_ALL

Test script:
---------------
Testing requires one to run curl from a host that is blocked by firewall to the remote host.

Cannot provide test script, hope strace is enough.

Can only reproduce with mod_php5, and not in CLI, perhaps due to environment variables.

Actual result:
--------------
stat("/var/www/example.com/vendor/guzzlehttp/ringphp/src/Core.php", {st_mode=S_IFREG|0644, st_size=11015, ...}) = 0
rt_sigaction(SIGALRM, NULL, {SIG_DFL, [], SA_RESTORER, 0x7f9168323710}, 8) = 0
rt_sigaction(SIGALRM, {0x7f9164198e40, [], SA_RESTORER, 0x7f9168323710}, NULL, 8) = 0
alarm(1)                                = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
alarm(0)                                = 1
rt_sigaction(SIGALRM, {SIG_DFL, [], SA_RESTORER, 0x7f9168323710}, NULL, 8) = 0
socket(PF_INET, SOCK_STREAM, IPPROTO_TCP) = 43
fcntl(43, F_GETFL)                      = 0x2 (flags O_RDWR)
fcntl(43, F_SETFL, O_RDWR|O_NONBLOCK)   = 0
connect(43, {sa_family=AF_INET, sin_port=htons(443), sin_addr=inet_addr("193.163.102.37")}, 16) = -1 EINPROGRESS (Operation now in progress)
poll([{fd=43, events=POLLOUT|POLLWRNORM}], 1, 500) = 0 (Timeout)
getsockopt(43, SOL_SOCKET, SO_ERROR, [0], [4]) = 0
close(43)                               = 0
socket(PF_INET6, SOCK_STREAM, IPPROTO_TCP) = 43
fcntl(43, F_GETFL)                      = 0x2 (flags O_RDWR)
fcntl(43, F_SETFL, O_RDWR|O_NONBLOCK)   = 0
connect(43, {sa_family=AF_INET6, sin6_port=htons(443), inet_pton(AF_INET6, "2a01:630:0:40::37", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = -1 ENETUNREACH (Network is unreachable)
open("/usr/share/locale/da_DK.ISO-8859-1/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/da_DK.iso88591/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/da_DK/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/da.ISO-8859-1/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/da.iso88591/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/usr/share/locale/da/LC_MESSAGES/libc.mo", O_RDONLY) = 44
fstat(44, {st_mode=S_IFREG|0644, st_size=129959, ...}) = 0
mmap(NULL, 129959, PROT_READ, MAP_PRIVATE, 44, 0) = 0x7f9169c43000
close(44)                               = 0
getsockopt(43, SOL_SOCKET, SO_ERROR, [0], [4]) = 0
close(43)                               = 0
access("/var/www/example.com/vendor/guzzlehttp/ringphp/src/Future/CompletedFutureArray.php", F_OK) = 0
stat("/var/www/example.com/vendor/guzzlehttp/ringphp/src/Future/CompletedFutureArray.php", {st_mode=S_IFREG|0644, st_size=866, ...}) = 0
access("/var/www/example.com/vendor/guzzlehttp/ringphp/src/Future/CompletedFutureValue.php", F_OK) = 0
stat("/var/www/example.com/vendor/guzzlehttp/ringphp/src/Future/CompletedFutureValue.php", {st_mode=S_IFREG|0644, st_size=1377, ...}) = 0
access("/var/www/example.com/vendor/guzzlehttp/ringphp/src/Future/FutureArrayInterface.php", F_OK) = 0
stat("/var/www/example.com/vendor/guzzlehttp/ringphp/src/Future/FutureArrayInterface.php", {st_mode=S_IFREG|0644, st_size=213, ...}) = 0
access("/var/www/example.com/vendor/guzzlehttp/ringphp/src/Exception/ConnectException.php", F_OK) = 0
stat("/var/www/example.com/vendor/guzzlehttp/ringphp/src/Exception/ConnectException.php", {st_mode=S_IFREG|0644, st_size=138, ...}) = 0
access("/var/www/example.com/vendor/guzzlehttp/ringphp/src/Exception/RingException.php", F_OK) = 0
stat("/var/www/example.com/vendor/guzzlehttp/ringphp/src/Exception/RingException.php", {st_mode=S_IFREG|0644, st_size=94, ...}) = 0
access("/var/www/example.com/vendor/react/promise/src/FulfilledPromise.php", F_OK) = 0
stat("/var/www/example.com/vendor/react/promise/src/FulfilledPromise.php", {st_mode=S_IFREG|0644, st_size=1791, ...}) = 0
access("/var/www/example.com/vendor/react/promise/src/ExtendedPromiseInterface.php", F_OK) = 0
stat("/var/www/example.com/vendor/react/promise/src/ExtendedPromiseInterface.php", {st_mode=S_IFREG|0644, st_size=584, ...}) = 0
access("/var/www/example.com/vendor/react/promise/src/PromiseInterface.php", F_OK) = 0
stat("/var/www/example.com/vendor/react/promise/src/PromiseInterface.php", {st_mode=S_IFREG|0644, st_size=226, ...}) = 0
access("/var/www/example.com/vendor/react/promise/src/CancellablePromiseInterface.php", F_OK) = 0
stat("/var/www/example.com/vendor/react/promise/src/CancellablePromiseInterface.php", {st_mode=S_IFREG|0644, st_size=166, ...}) = 0
access("/var/www/example.com/vendor/guzzlehttp/guzzle/src/Exception/RequestException.php", F_OK) = 0
stat("/var/www/example.com/vendor/guzzlehttp/guzzle/src/Exception/RequestException.php", {st_mode=S_IFREG|0644, st_size=3420, ...}) = 0
access("/var/www/example.com/vendor/guzzlehttp/guzzle/src/Exception/TransferException.php", F_OK) = 0
stat("/var/www/example.com/vendor/guzzlehttp/guzzle/src/Exception/TransferException.php", {st_mode=S_IFREG|0644, st_size=92, ...}) = 0
access("/var/www/example.com/vendor/guzzlehttp/guzzle/src/Exception/ConnectException.php", F_OK) = 0
stat("/var/www/example.com/vendor/guzzlehttp/guzzle/src/Exception/ConnectException.php", {st_mode=S_IFREG|0644, st_size=90, ...}) = 0
access("/var/www/example.com/vendor/guzzlehttp/guzzle/src/Event/ErrorEvent.php", F_OK) = 0
stat("/var/www/example.com/vendor/guzzlehttp/guzzle/src/Event/ErrorEvent.php", {st_mode=S_IFREG|0644, st_size=676, ...}) = 0
access("/var/www/example.com/vendor/guzzlehttp/guzzle/src/Event/AbstractRetryableEvent.php", F_OK) = 0
stat("/var/www/example.com/vendor/guzzlehttp/guzzle/src/Event/AbstractRetryableEvent.php", {st_mode=S_IFREG|0644, st_size=1473, ...}) = 0
access("/var/www/example.com/vendor/guzzlehttp/guzzle/src/Event/AbstractTransferEvent.php", F_OK) = 0
stat("/var/www/example.com/vendor/guzzlehttp/guzzle/src/Event/AbstractTransferEvent.php", {st_mode=S_IFREG|0644, st_size=1825, ...}) = 0
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
chdir("/usr/local/apache2")             = 0
rt_sigaction(SIGSEGV, {SIG_DFL, [], SA_RESTORER|SA_INTERRUPT, 0x7f9168323710}, {SIG_DFL, [], SA_RESTORER|SA_RESETHAND, 0x7f9168323710}, 8) = 0
kill(23746, SIGSEGV)                    = 0
rt_sigreturn(0x5cc2)                    = 0
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
Process 23746 detached