0.3.0: converge relibc to upstream 0.6.0 + Red Bear patches

tests/sys_socket/unixwrite.c

@@ -0,0 +1,56 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include "test_helpers.h"
+
+// similar to "unixrecv", but this test if write() works before accept().
+// "unixrecvfrom" is the similar test to this one, but using SOCK_DGRAM.
+// "unixrecvearly" is also the similar test to this one, but using recv().
+int main() {
+    int status;
+    const char* socket_path = "unix_write.sock";
+    unlink(socket_path);
+
+    int server_fd = socket(AF_UNIX, SOCK_STREAM, 0);
+    ERROR_IF(socket, server_fd, == -1);
+
+    struct sockaddr_un addr = { .sun_family = AF_UNIX };
+    strncpy(addr.sun_path, socket_path, sizeof(addr.sun_path) - 1);
+
+    unlink(socket_path);
+
+    status = bind(server_fd, (struct sockaddr*)&addr, sizeof(addr));
+    ERROR_IF(bind, status, == -1);
+
+    status = listen(server_fd, 1);
+    ERROR_IF(listen, status, == -1);
+
+    int client_fd = socket(AF_UNIX, SOCK_STREAM, 0);
+    ERROR_IF(socket, client_fd, == -1);
+
+    status = connect(client_fd, (struct sockaddr*)&addr, sizeof(addr));
+    ERROR_IF(connect, status, == -1);
+
+    char *msg = "yes";
+    ssize_t ret = write(client_fd, msg, 4);
+    ERROR_IF(write, ret, == -1);
+    UNEXP_IF(raise, ret, != 4);
+
+    int accepted_fd = accept(server_fd, NULL, NULL);
+    ERROR_IF(accept, accepted_fd, == -1);
+
+    char x[4];
+    ssize_t amount = read(accepted_fd, x, 4);
+    ERROR_IF(read, amount, == -1);
+
+    close(accepted_fd);
+    close(client_fd);
+    close(server_fd);
+    return 0;
+}