negate should pass stderr unaltered, instead of redirecting to stdout.

Also do not alter the child's status based solely on the presence of
stderr output, this can change the child's behaviour in unexpected ways.

plugins/negate.c

@@ -85,17 +85,10 @@ main (int argc, char **argv)
 	} else {
 		result = cmd_run_array (command_line, &chld_out, &chld_err, 0);
 	}
-	if (chld_err.lines > 0) {
-		printf ("Error output from command:\n");
-		for (i = 0; i < chld_err.lines; i++) {
-			printf ("%s\n", chld_err.line[i]);
-		}
-		exit (STATE_WARNING);
-	}
 
-	/* Return UNKNOWN or worse if no output is returned */
-	if (chld_out.lines == 0)
-		die (max_state_alt (result, STATE_UNKNOWN), _("No data returned from command\n"));
+	for (i = 0; i < chld_err.lines; i++) {
+		fprintf (stderr, "%s\n", chld_err.line[i]);
+	}
 
 	for (i = 0; i < chld_out.lines; i++) {
 		if (subst_text && result >= 0 && result <= 3 && result != state[result])  {