git-svn: gracefully handle --follow-parent failures
git-svn: gracefully handle --follow-parent failures

We don't always know that a path will exist at a particular
revision.

Signed-off-by: Eric Wong <8c2951295f8292b0c03727bc4652981172298eae@yhbt.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git