test: fix parser to prefer binop over unop, as coreutils does.

 remove bogus workaround in main(). rename atrocious variables/functions.
 much expand testsuite.
libbb: fix --help to not affect "test --help"

function                                             old     new   delta
run_applet_no_and_exit                               421     440     +19
nexpr                                                817     825      +8
static.no_op                                           -       6      +6
test_main                                            397     257    -140
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 2/1 up/down: 104/-211)         Total: -107 bytes

1 files changed, 13 insertions, 4 deletions

diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index eb98f1c..8c35450 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -196,8 +196,12 @@ void lbb_prepare(const char *applet
 #if ENABLE_FEATURE_INDIVIDUAL
 	/* Redundant for busybox (run_applet_and_exit covers that case)
 	 * but needed for "individual applet" mode */
-	if (argv[1] && strcmp(argv[1], "--help") == 0)
-		bb_show_usage();
+	if (argv[1] && !argv[2] && strcmp(argv[1], "--help") == 0) {
+		/* Special case. POSIX says "test --help"
+		 * should be no different from e.g. "test --foo".  */
+		if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
+			bb_show_usage();
+	}
 #endif
 }
 
@@ -715,8 +719,13 @@ void FAST_FUNC run_applet_no_and_exit(int applet_no, char **argv)
 	xfunc_error_retval = EXIT_FAILURE;
 
 	applet_name = APPLET_NAME(applet_no);
-	if (argc == 2 && !strcmp(argv[1], "--help"))
-		bb_show_usage();
+	if (argc == 2 && strcmp(argv[1], "--help") == 0) {
+		/* Special case. POSIX says "test --help"
+		 * should be no different from e.g. "test --foo".  */
+//TODO: just compare applet_no with APPLET_NO_test
+		if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
+			bb_show_usage();
+	}
 	if (ENABLE_FEATURE_SUID)
 		check_suid(applet_no);
 	exit(applet_main[applet_no](argc, argv));