RFR: Make ext.py compatible with hg5 api

[Erik Duveblad via github.com]

On Thu, 22 Aug 2019 12:04:42 GMT, Jorn Vernee via github.com <duke at openjdk.java.net> wrote:

> The HG api changes in version 5 to drop the first 2 parameters to `mercurial.match.exact`, which breaks the extension script.
> 
> This PR detects whether we're running on hg 5, and if so, calls the function without the first 2 arguments instead.
> 
> ----------------
> 
> Commits:
>  - 741ee3e3:	Make ext.py compatible with hg5 api
> 
> Pull request:
> https://git.openjdk.java.net/skara/pull/67
> 
> Webrev:
> https://webrevs.openjdk.java.net/skara/67/webrev.00
> 
> Patch:
> https://git.openjdk.java.net/skara/pull/67.diff
> 
> Fetch command:
> git fetch https://git.openjdk.java.net/skara pull/67/head:pull/67

vcs/src/main/resources/ext.py line 62:

> 61:     Wrapper for mercurial.match.exact that ignores some arguments based on the used version
> 62:     """
> 63:     if mercurial.util.versiontuple() < 5:

Two questions here:
1. How does this check work? `versiontuple()` returns a tuple, e.g. `(4, 9, 2)`, how can you compare a tuple to an `int`?
2. `mercurial.util.versiontuple()` is fairly new (added 2015) whereas `mercurial.util.version()` has been around since 2009. Is it possible to implement the check using `mercurial.util.version()` instead? Like `mercurial.util.version().startswith("5")`?

PR: https://git.openjdk.java.net/skara/pull/67