Re: [ltree] Should `SELECT LCA('1.2', '1.2.3');` return '1.2' instead of '1'?

2017-12-01 17:17 GMT+01:00 David G. Johnston <david(dot)g(dot)johnston(at)gmail(dot)com>:

> ​[…] Adding a leading (due to varargs) boolean argument that specifies
> "end node is ancestor of itself" behavior might be a workable solution.
>

> Regardless, the docs should be clarified on this point, though, and maybe
> add a code comment somewhere.
>

I understand the importance not to break existing usages. It would be
perfect to have a boolean to specify that – and to clarify the docs, since
the example given does not reveal this behavior
https://www.postgresql.org/docs/9.1/static/ltree.html#LTREE-FUNC-TABLE

I digged inside the source code and ended at
`contrib/ltree/ltree_op.c:406` but I don't feel able to do the patch.