Issue with libhyphen

Dear László and others,

We think we may have found a bug in libhyphen. It could be that it is just
a limitation of the algorithm, but anyway it's an issue for us.

The problem is that some patterns in a dictionary are ignored in some
cases, namely when the match string of that pattern is a part of the match
string of another pattern, and more specifically when it's not just a
prefix.

Let me clarify that with an example. When a dictionary consists of these
two patterns, the word `foobar' is not hyphenated because the first pattern
is ignored:

oo1b
foob

The second, longer pattern doesn't even have to match, as the second
example shows (the first pattern is still ignored):

oo1b
foobz

I have a patch that solves part of the problem:

https://github.com/bertfrees/libhyphen-nar/blob/adc2b74a19469e4dc93777fcdb82e36e566a0472/src/patches/bug.patch

With this patch the given examples will be handled correctly, but in other
situations it will still fail, such as here:

oo1b
foobaz

Have I indeed found a bug here, and does my patch make sense, or am I just
expecting too much and are we hitting the limits of the algorithm?

Thanks for considering,
Bert Frees