[PATCH 0/2] git-svn: silence bogus v1-layout migration message

While running `dzil build' (a Perl tool for minting and shipping
modules) without a git remote configured, git started printing
"Migrating from a git-svn v1 layout..." messages. In addition it also
created an empty `.git/svn' directory. After removing that directory, it
again repeated the behaviour on every `dzil build' invocation.

One of the plugins runs `git svn info' to probe whether the repo is an
SVN checkout. On a plain git-only repository this produced a wall of
migration text on the terminal and left behind an empty `.git/svn'
directory. I initially thought it was just a plugin being weird, but
running `git svn info' myself turned out to be the real "troublemaker".

You can do reproduce the behaviour by doing:

  git init .
  git svn info

This patch addresses that and uses the same pattern as
`migrate_from_v0'. I've included tests to t9107.

In addition, which was my intitial reaction: I've added a knob to
exclude git svn from being installed. When you add
`NO_GIT_SVN=YesPlease' to your make invocation, git is installed without
git-svn and no SVN tests run.

Wesley Schwengle (2):
  git-svn: don't print v1-layout migration noise when there's nothing to
    migrate
  Makefile: add NO_GIT_SVN knob to skip building/installing git-svn

 Makefile                   |  8 ++++++++
 perl/Git/SVN/Migration.pm  | 16 ++++++++++------
 t/t9107-git-svn-migrate.sh |  7 +++++++
 3 files changed, 25 insertions(+), 6 deletions(-)

-- 
2.55.0.827.g48ce2c92dc