gcc7 fall-through warning (and fix)

[sgbeal]

gcc7, in its infinite braindeadedness, warns when a switch's case statement will fall through, and this causes 1 warning in regexp.c:

egexp.c:125:11: warning: this statement may fall through [-Wimplicit-fallthrough=]
   case 0: die("unterminated escape sequence");
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In this case it's trivial to solve by adding:

; return 0

after the call to die(). It won't ever return, so the return is harmless.

That said: the use of die() makes this code ill-suited for use in a library :( - we can't kill the app just because a user inputs an invalid regex:

[stephan@host:~/cvs/minilibs]$ ./test_regexp.exe '\bbl(e+)p\b\' 'foo bar bleep baz bleeeeep'
regcomp: unterminated escape sequence

If you can tell that this code is public domain, MIT, or has a similar non-viral license, i will refactor it for use as a library and contribute the changes back to you.

[sgbeal]

Nevermind: this is addressed (indirectly) by issue #1. i'll take a look at the copy to linked there.

[ccxvii]

The die() function call just longjmps to an error handler in regcomp, which returns an error code to the user.

The version in mujs is thread safe by putting all the "global" state on the stack, so is likely of more use to you.

[sgbeal]

Definitely - i have already extracted it and will start hacking it for use with my library later today. :)