[PATCH] fix test/[ exit status on invalid operand

[Martijn Dekker]

The mksh implementation of test/[ incorrectly returns an exit status of
0 (success) if one of the operands to an operator is invalid. An example:

$ test 2 -eq 2a && echo false-positive
mksh: 2a: bad number '2a'
false-positive

I wrote the attached patch which I believe fixes the problem. Please verify.

Thanks,

- Martijn Dekker (Groningen, Netherlands)

diff -ur mksh.orig/funcs.c mksh/funcs.c
--- mksh.orig/funcs.c	2015-07-11 01:01:24.000000000 +0100
+++ mksh/funcs.c	2015-12-11 21:44:19.000000000 +0000
@@ -2861,7 +2861,10 @@
  ptest_unary:
 			rv = test_eval(&te, op, *te.pos.wp++, NULL, true);
  ptest_out:
-			return ((invert & 1) ? rv : !rv);
+			if (te.flags & TEF_ERROR)
+				return (T_ERR_EXIT);
+			else
+				return ((invert & 1) ? rv : !rv);
 		}
 		/* let the parser deal with anything else */
 		break;