test: fix mishandling of 'test ! arg1 op arg2 more args'; add testsuite

diff --git a/coreutils/test.c b/coreutils/test.c
index a30a508..22dadac 100644
--- a/coreutils/test.c
+++ b/coreutils/test.c
@@ -555,7 +555,7 @@
 {
 	int res;
 	const char *arg0;
-	bool _off;
+	bool negate = 0;
 
 	arg0 = bb_basename(argv[0]);
 	if (arg0[0] == '[') {
@@ -578,9 +578,8 @@
 	INIT_S();
 
 	res = setjmp(leaving);
-	if (res) {
+	if (res)
 		goto ret;
-	}
 
 	/* resetting ngroups is probably unnecessary.  it will
 	 * force a new call to getgroups(), which prevents using
@@ -592,34 +591,40 @@
 	 */
 	ngroups = 0;
 
+	//argc--;
+	argv++;
+
 	/* Implement special cases from POSIX.2, section 4.62.4 */
-	if (argc == 1) {
+	if (!argv[0]) { /* "test" */
 		res = 1;
 		goto ret;
 	}
-	if (argc == 2) {
-		res = (*argv[1] == '\0');
+	if (LONE_CHAR(argv[0], '!') && argv[1]) {
+		negate = 1;
+		//argc--;
+		argv++;
+	}
+	if (!argv[1]) { /* "test [!] arg" */
+		res = (*argv[0] == '\0');
 		goto ret;
 	}
-
-	/* remember if we saw argc==4 which wants *no* '!' test */
-	_off = argc - 4;
-	if (_off ? (LONE_CHAR(argv[1], '!'))
-	         : (argv[1][0] != '!' || argv[1][1] != '\0')
-	) {
-		if (argc == 3) {
-			res = (*argv[2] != '\0');
-			goto ret;
-		}
-
-		t_lex(argv[2 + _off]);
+	if (argv[2] && !argv[3]) {
+		t_lex(argv[1]);
 		if (t_wp_op && t_wp_op->op_type == BINOP) {
-			t_wp = &argv[1 + _off];
-			res = (binop() == _off);
+			/* "test [!] arg1 <binary_op> arg2" */
+			t_wp = &argv[0];
+			res = (binop() == 0);
 			goto ret;
 		}
 	}
-	t_wp = &argv[1];
+
+	/* Some complex expression. Undo '!' removal */
+	if (negate) {
+		negate = 0;
+		//argc++;
+		argv--;
+	}
+	t_wp = &argv[0];
 	res = !oexpr(t_lex(*t_wp));
 
 	if (*t_wp != NULL && *++t_wp != NULL) {
@@ -628,5 +633,5 @@
 	}
  ret:
 	DEINIT_S();
-	return res;
+	return negate ? !res : res;
 }