We now try to walk changesets in reverse order from newest to oldest,
so that if we see a file multiple times, we treat the newest version
as canonical.
This should prevent us from rejecting a changegroup that contains an
unacceptable commit followed later by a commit that fixes the problem.
This can make a difference when there are filters involved and
decode(encode(working-dir-data)) != working-dir-data
even though
encode(decode(repo-data)) == repo-data
An example is a working dir file that uses only \n when you're using
the win32text extension.
While some can function with just some text and an optional command name,
others may want a repository object, a ui object, and a file path.
Use the enhanced information to good effect in win32text.dumbdecode's warning.
While the win32text extension does LF <-> CRLF conversion, and will issue a
warning in case a file already in the repository uses CRLF, it provides no
mechanism for verifying that incoming changes use LF. In a large development
team with some Windows users, it is virtually guaranteed that someone will
forget to set up the encode filter correctly and accidentally check in a file
using CRLF, which can cause warnings for other Windows users when they next
fetch changes. Since this is a general problem it is desirable to have a
pre-commit (or -push) hook available to reject such accidents earlier rather
than trying to fix them up after the fact.
