Why wasn't this noticed? Although many tests use kill, none of
them made an effort to avoid using the shell's built-in kill.
- [ invoked with no arguments no longer evokes a segfault
+- expr now exits with status 2 if the expression is syntactically valid,
+ and with status 3 if an error occurred. POSIX requires this.
+- expr now reports trouble if string comparison fails due to a collation error.
* Major changes in release 5.0.1: