include/openssl/e_os2.h: define last-resort SSIZE_MAX.
@@ -216,6 +216,8 @@ extern "C" {
# define OSSL_SSIZE_MAX SSIZE_MAX
# elif defined(_POSIX_SSIZE_MAX)
# define OSSL_SSIZE_MAX _POSIX_SSIZE_MAX
+# else
+# define OSSL_SSIZE_MAX ((ssize_t)(SIZE_MAX>>1))
# endif
# endif
