git-svn: add --follow-parent and --no-metadata options to fetch

--follow-parent:
  This is especially helpful when we're tracking a directory
  that has been moved around within the repository, or if we
  started tracking a branch and never tracked the trunk it was
  descended from.

  This relies on the SVN::* libraries to work.  We can't
  reliably parse path info from the svn command-line client
  without relying on XML, so it's better just to have the SVN::*
  libs installed.

  This also removes oldvalue verification when calling update-ref

  In SVN, branches can be deleted, and then recreated under the
  same path as the original one with different ancestry
  information, causing parent information to be mismatched /
  misordered.

  Also force the current ref, if existing, to be a parent,
  regardless of whether or not it was specified.

--no-metadata:
  This gets rid of the git-svn-id: lines at the end of every commit.

  With this, you lose the ability to use the rebuild command.  If
  you ever lose your .git/svn/git-svn/.rev_db file, you won't be
  able to fetch again, either.  This is fine for one-shot imports.

  Also fix some issues with multi-fetch --follow-parent that were
  exposed while testing this.  Additionally, repack checking is
  simplified greatly.

  git-svn log will not work on repositories using this, either.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>

contrib/git-svn/t/t0004-follow-parent.sh

@@ -0,0 +1,44 @@
+#!/bin/sh
+#
+# Copyright (c) 2006 Eric Wong
+#
+
+test_description='git-svn --follow-parent fetching'
+. ./lib-git-svn.sh
+
+if test -n "$GIT_SVN_NO_LIB" && test "$GIT_SVN_NO_LIB" -ne 0
+then
+	echo 'Skipping: --follow-parent needs SVN libraries'
+	test_done
+	exit 0
+fi
+
+test_expect_success 'initialize repo' "
+	mkdir import &&
+	cd import &&
+	mkdir -p trunk &&
+	echo hello > trunk/readme &&
+	svn import -m 'initial' . $svnrepo &&
+	cd .. &&
+	svn co $svnrepo wc &&
+	cd wc &&
+	echo world >> trunk/readme &&
+	svn commit -m 'another commit' &&
+	svn up &&
+	svn mv -m 'rename to thunk' trunk thunk &&
+	svn up &&
+	echo goodbye >> thunk/readme &&
+	svn commit -m 'bye now' &&
+	cd ..
+	"
+
+test_expect_success 'init and fetch --follow-parent a moved directory' "
+	git-svn init -i thunk $svnrepo/thunk &&
+	git-svn fetch --follow-parent -i thunk &&
+	git-rev-parse --verify refs/remotes/trunk &&
+	test '$?' -eq '0'
+	"
+
+test_debug 'gitk --all &'
+
+test_done