Take a getopt_long() patch from upstream FreeBSD.

  r342757 | kevans | 2019-01-03 19:13:24 -0800 (Thu, 03 Jan 2019) | 19 lines

  getopt_long(3): fix case of malformed long opt

  When presented with an arg string like '-l-', getopt_long will successfully
  parse out the 'l' short option, then proceed to match '--' against the first
  longopts entry as it later does a strncmp with len=0. This latter bit is
  arguably another bug in itself, but presumably not a practical issue as all
  callers of parse_long_options are already doing the right thing (except this
  one pointed out).

  An opt string like '-l-' should be considered malformed and throw a bad
  argument rather than behaving as if '--' were passed. It cannot possibly do
  what the invoker expects, and it's probably the result of a typo (ls -l- a)
  rather than any intent.

  Reported by:	Tony Overfield <toverfield@yahoo.com>
  Reviewed by:	imp
  MFC after:	2 weeks
  Differential Revision:	https://reviews.freebsd.org/D18616

Test: treehugger
Change-Id: I593713bc35d70eb1975c9d7587528f2b3f9731af
diff --git a/libc/upstream-freebsd/lib/libc/stdlib/getopt_long.c b/libc/upstream-freebsd/lib/libc/stdlib/getopt_long.c
index 9534a2a..6a3067c 100644
--- a/libc/upstream-freebsd/lib/libc/stdlib/getopt_long.c
+++ b/libc/upstream-freebsd/lib/libc/stdlib/getopt_long.c
@@ -55,7 +55,7 @@
 #endif /* LIBC_SCCS and not lint */
 #endif
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
+__FBSDID("$FreeBSD: head/lib/libc/stdlib/getopt_long.c 342757 2019-01-04 03:13:24Z kevans $");
 
 #include <err.h>
 #include <errno.h>
@@ -481,6 +481,8 @@
 #endif
 		if (*place == '-') {
 			place++;		/* --foo long option */
+			if (*place == '\0')
+				return (BADARG);	/* malformed option */
 #ifdef GNU_COMPATIBLE
 			dash_prefix = DD_PREFIX;
 #endif